Computational models of cognitive processes may be employed in cyber-security tools, experiments, and simulations to address human agency and effective decision-making in keeping computational ...networks secure. Cognitive modeling can addresses multi-disciplinary cyber-security challenges requiring cross-cutting approaches over the human and computational sciences such as the following: (a) adversarial reasoning and behavioral game theory to predict attacker subjective utilities and decision likelihood distributions, (b) human factors of cyber tools to address human system integration challenges, estimation of defender cognitive states, and opportunities for automation, (c) dynamic simulations involving attacker, defender, and user models to enhance studies of cyber epidemiology and cyber hygiene, and (d) training effectiveness research and training scenarios to address human cyber-security performance, maturation of cyber-security skill sets, and effective decision-making. Models may be initially constructed at the group-level based on mean tendencies of each subject's subgroup, based on known statistics such as specific skill proficiencies, demographic characteristics, and cultural factors. For more precise and accurate predictions, cognitive models may be fine-tuned to each individual attacker, defender, or user profile, and updated over time (based on recorded behavior) via techniques such as model tracing and dynamic parameter fitting.
Cybersecurity stands to benefit greatly from models able to generate predictions of attacker and defender behavior. On the defender side, there is promising research suggesting that Symbolic Deep ...Learning (SDL) may be employed to automatically construct cognitive models of expert behavior based on small samples of expert decisions. Such models could then be employed to provide decision support for non-expert users in the form of explainable expert-based suggestions. On the attacker side, there is promising research suggesting that model-tracing with dynamic parameter fitting may be used to automatically construct models during live attack scenarios, and to predict individual attacker preferences. Predicted attacker preferences could then be exploited for mitigating risk of successful attacks. In this paper we examine how these two cognitive modeling approaches may be useful for cybersecurity professionals via two human experiments. In the first experiment participants play the role of cyber analysts performing a task based on Intrusion Detection System alert elevation. Experiment results and analysis reveal that SDL can help to reduce missed threats by 25%. In the second experiment participants play the role of attackers picking among four attack strategies. Experiment results and analysis reveal that model-tracing with dynamic parameter fitting can be used to predict (and exploit) most attackers' preferences 40-70% of the time. We conclude that studies and models of human cognition are highly valuable for advancing cybersecurity.
We observe a trend between initial leakage currents in polycrystalline HfO x resisitive random access memory (RRAM) cells (before forming) and the forming voltages. This trend points to the dominant ...role played by conduction paths located at grain boundaries, which is promoted by the oxygen deficiency in HfO x . One of these paths is then converted into the conductive filament responsible for nonvolatile resistance switching. In addition, we find that by engineering the RRAM stack, the forming voltage can be tuned-up to meet specific RRAM requirements, such as lower power and forming-less operations.
Defect generation controlling device degradation is found to be highly sensitive to the signal duration in circuitry-relevant operation frequencies (GHz). Stressing devices in ns-time range reveals ...greatly extended device lifetimes compared to conventional evaluation conditions. The role of energy generation/dissipation in scaled devices is discussed.
We observe a gamma-irradiation-induced change in electrically detected magnetic resonance (EDMR) in TiN/Ti/HfO 2 /TiN resistive random access memory (RRAM). EDMR measurements exclusively detect ...electrically active defects, which are directly involved in the transport mechanisms within these devices. The EDMR response has an isotropic g value of 2.001 ± 0.0003. The response increases dramatically with increased gamma irradiation. We tentatively associate this EDMR response with spin-dependent trap-assisted tunneling events at O 2 − centers coupled to hafnium ions. Although our study cannot fully identify the role of these defects in electronic transport, the study does unambiguously identify changes in transport defects caused by the ionizing radiation on defects involved in electronic transport in RRAM devices. This paper also contributes more broadly to the RRAM field by providing direct, though incomplete, information about atomic scale defects involved in electronic transport in leading RRAM systems.
Detection of subterahertz and terahertz radiation by high electron mobility GaN/AlGaN transistors in the 0.2-2.5THz frequency range (much higher than the cutoff frequency of the transistors) is ...reported. Experiments were performed in the temperature range 4-300K. For the lowest temperatures, a resonant response was observed. The resonances were interpreted as plasma wave excitations in gated two-dimensional electron gas. Non-resonant detection was observed at temperatures above 100K. Estimates for noise equivalent power show that these transistors can be used as efficient detectors of terahertz radiation at cryogenic and room temperatures.
In this letter, we use gated Hall method for direct measurement of free carrier density and electron mobility in inversion InGaAs MOSFET channels. At room temperature, the highest Hall mobility of ...1800 cm 2 /Vs is observed at electron density in the channel ≈1 × 10 12 cm -2 . A comparison with mobility values estimated from transistor characteristics reveals a significant underestimation of mobility, which arises from overestimation of channel density obtained from C-V measurements. Temperature dependence of the electron mobility provides the evidence that remote Coulomb scattering dominates at electron density <;3 × 10 11 cm -2 . Contrary to the capacitance-based methods commonly used for extraction of interface trap density, a gated Hall method can separate the contributions of fast-trapped charges and free carriers in the channel to the total charge of a MOS capacitor. This allows for reliable estimation of trap density at the III-V/high-k interface including border traps. The results illustrate that even high-quality interfaces providing high-mobility transport suffer from fast border traps above the conduction band. In contrast with Si where the effect of border traps is negligible, in low density-of-state InGaAs channel material as much as half of the channel electrons can be trapped and excluded from transport, increasing switching energy and dissipated power.
Despite extensive research, it is still difficult to produce effective interactive layouts for large graphs. Dense layout and occlusion make food Webs, ontologies and social networks difficult to ...understand and interact with. We propose a new interactive visual analytics component called TreePlus that is based on a tree-style layout. TreePlus reveals the missing graph structure with visualization and interaction while maintaining good readability. To support exploration of the local structure of the graph and gathering of information from the extensive reading of labels, we use a guiding metaphor of "plant a seed and watch it grow." It allows users to start with a node and expand the graph as needed, which complements the classic overview techniques that can be effective at (but often limited to) revealing clusters. We describe our design goals, describe the interface and report on a controlled user study with 28 participants comparing TreePlus with a traditional graph interface for six tasks. In general, the advantage of TreePlus over the traditional interface increased as the density of the displayed data increased. Participants also reported higher levels of confidence in their answers with TreePlus and most of them preferred TreePlus
We observe a gamma-irradiation induced change in electrically detected magnetic resonance (EDMR) in TiN/Ti/HfO
/TiN resistive random access memory (RRAM). EDMR measurements exclusively detect ...electrically active defects which are directly involved in the transport mechanisms within these devices. The EDMR response has an isotropic g-value of 2.001 ± 0.0003. The response increases dramatically with increased gamma-irradiation. We tentatively associate this EDMR response with spin dependent trap assisted tunneling (SDTAT) events at
centers coupled to hafnium ions. Although our study cannot fully identify the role of these defects in electronic transport, the study does unambiguously identify changes in transport defects caused by the ionizing radiation on defects involved in electronic transport in RRAM devices. This work also contributes more broadly to the RRAM field by providing direct, though incomplete, information about atomic scale defects involved in electronic transport in leading RRAM systems.
Results of room temperature measurement of nonresonant sub-terahertz detection by nanoscale silicon MOSFETs under a variety of load conditions are reported. The effect of device loading is ...incorporated into existing response models to explain diminished response in the sub-threshold region, and calculation of noise equivalent power indicates minima near the threshold voltage.
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