Network Proactive Defense Model Based on Immune Danger Theory

Recent investigations into proactive network defense have not produced a systematic methodology and structure; in addition, issues including multi-source information fusion and attacking behavior analysis have not been resolved. Borrowing ideas of danger sensing and immune response from danger theory, a proactive network defense model based on danger theory is proposed. This paper defines the signals and antigens in the network environment as well as attacking behavior analysis algorithm, providing evidence for future proactive defense strategy selection. The results of preliminary simulations demonstrate that this model can sense the onset of varied network attacks and corresponding endangered intensities, which help to understand the attack methods of hackers and assess the security situation of the current network, thus a better proactive defense strategy can be deployed. Moreover, this model possesses good robustness and accuracy

Warm hilltop inflation

We study the low-temperature limit of warm inflation in a hilltop model. This limit remains valid up to the end of inflation, allowing an analytic description of the entire inflationary stage. In the weak dissipative regime, if the kinetic density of the inflaton dominates after inflation, low scale inflation is attained with Hubble scale as low as 1 GeV. In the strong dissipative regime, the model satisfies the observational requirements for the spectral index with a mild tuning of the model parameters, while also overcoming the $\eta$-problem of inflation. However, there is some danger of gravitino overproduction unless the particle content of the theory is large.Comment: 9 pages, 2 figure

Dynamical fidelity of a solid-state quantum computation

In this paper we analyze the dynamics in a spin-model of quantum computer. Main attention is paid to the dynamical fidelity (associated with dynamical errors) of an algorithm that allows to create an entangled state for remote qubits. We show that in the regime of selective resonant excitations of qubits there is no any danger of quantum chaos. Moreover, in this regime a modified perturbation theory gives an adequate description of the dynamics of the system. Our approach allows to explicitly describe all peculiarities of the evolution of the system under time-dependent pulses corresponding to a quantum protocol. Specifically, we analyze, both analytically and numerically, how the fidelity decreases in dependence on the model parameters.Comment: 9 pages, 6 figures, submitted to PR

Dust emission by powder handling: Comparison between numerical analysis and experimental results

The dust generation occurring during the handling of bulk materials in free falls or at the impact on a stockpile can be a source of danger for the operators health. Proper design of control systems of fugitive dust requires knowledge of the behavior of the free falling powder, the air it entrains, and the concentration of dust liberated. This paper presents first a simple model for a free falling column of bulk solids and compares it with relevant previous research. This two phase model predicts the particle and air velocities, and especially the volumetric flow of induced air in the column without dependence on any empirical constant like the entrainment constant used in the plume model. For small drop heights, the predictions of the theory appear to be in qualitative agreement with the available data for the quantity of air entrained, but the theory needs to be extended in the case of large drop heights, when the expansion of the jet of particles is large. In a second part, the description of an expanded jet of particles is experimentally studied with PIV measurements. The data obtained are well fitted by the model by Liu, when the entrainment constant is taken as the angle of expansion of the jet obtained from the velocity field

Evaluating the Role of Environmental Stressors and Sensitive Parenting on the Emergence of Behavior Problems during Early Childhood

Repeatedly, parenting quality has been shown to affect children’s level of behavior problems during early childhood (e.g., Bayer, Sanson, & Hemphill, 2006; Shaw, Gilliom, Ingoldsby, & Nagin, 2003). However, the parent-child relationship exists within a broader social context (Bronfenbrenner, 1986). Therefore, social contextual stressors such as financial strain, neighborhood danger, and residential overcrowding may affect children’s adjustment through parenting. Based on The Family Stress model (Conger & Elder, 1994), the current study tests the theory that sensitive parenting mediates the relationship between these three environmental stressors (i.e., financial strain, neighborhood danger, and residential overcrowding) and children’s behavior problems from ages 2 to 4 years. Results did not support this hypothesis. Though, alternative analyses provided some support for interactive effects of sensitive parenting and neighborhood danger on children’s externalizing problems. When families experienced less neighborhood danger, sensitive parenting was associated with less externalizing problems

Dynamic Model of Credit Risk in Relationship Lending: A Game- theoretic Real Options Approach

We develop a dynamic credit risk model for the case that banks compete to collect their loans from a firm falling in danger of bankruptcy. We apply a game-theoretic real options approach to investigate bankfs optimal strategies. Our model reveals that the bank with the larger loan amount, namely the main bank, provides an additional loan to support the deteriorating firm when the other bank collects its loan. This suggests that there exists rational forbearance lending by the main bank. Comparative statics show that as the liquidation value is lower, the optimal exit timing for the non-main bank comes at an earlier stage of business downturn and the optimal liquidation timing by the main bank is delayed further. As the interest rate of the loan is lower, the optimal exit timing for the non-main bank comes earlier. These analyses are consistent with the forbearance lending and exposure concentration of main banks observed in Japan.Credit risk, Relationship lending, Real option, Game theory, Concentration risk

Dynamic Model of Credit Risk in Relationship Lending: A Game- Theoretic Real Options Approach

We develop a dynamic credit risk model for the case in which banks compete to collect their loans from a firm in danger of bankruptcy. We apply a game-theoretic real options approach to investigate banksf optimal strategies. Our model reveals that the bank with the larger loan amount, namely, the main bank, provides an additional loan to support the deteriorating firm when the other bank collects its loan. This suggests that there exists rational forbearance lending by the main bank. Comparative statics show that as the liquidation value is lower, the optimal exit timing for the nonmain bank comes at an earlier stage in the business downturn and the optimal liquidation timing by the main bank is delayed further. As the interest rate of the loan is lower, the optimal exit timing for the non-main bank comes earlier. These analyses are consistent with the forbearance lending and exposure concentration of main banks observed in Japan.Credit risk; Relationship lending; Real option; Game theory; Concentration risk