Blow-up criteria for Boussinesq system and MHD system and Landau-Lifshitz equations in a bounded domain

In this paper, we prove some blow-up criteria for the 3D Boussinesq system with zero heat conductivity and MHD system and Landau-Lifshitz equations in a bounded domain.Comment: 20 page

Multiple Scale Impacts of Nomad Settlement on Social-Ecological Systems

There are complex interactions and feedback mechanisms between human and natural systems within the coupled social-ecological systems (SESs) (Liu et al. 2007, Li and Li 2012). Human society is the major driving force that changes ecosystem dynamics from local environments to the biosphere (Liu et al. 2007, Kirch 2005). Grasslands, especially the vulnerable arid and semi-arid grassland ecosystems upon which pastoralists live and graze livestock, can be considered as SESs; pastoral activities influence the biophysical environment and set up interactions between the components of these systems (Robinson 2009). In recent years, the ecosystem services provided by grasslands and the problem of poverty in grassland communities have attracted increasing attention from governments and society in China. One response has been the Nomad Settlement Projects (NSPs), implemented as a development strategy in pastoral areas to find solutions to the prevailing ecological and social problems. Nomadic people were provided with houses and farmland in some place, and encouraged to settle down and modernize the “backward” pastoralism. In this paper, we explored the impacts of China’s Nomad Sedentarization Project (NSP) for pastoral areas on coupled social and ecological systems by evaluating the consequences of these projects at different scales (village scale, county scale and catchment scale) undertaken in grassland SESs, including the ecological and social consequences. China\u27s government is now promoting the NSP in large areas of grassland as a solution for ecological restoration and poverty alleviation. To determine the effects of this policy, we conducted in-depth interviews at two of the project\u27s sites and examined the social and ecological systems at village, county, and catchment scales

A Novel SDN based Stealthy TCP Connection Handover Mechanism for Hybrid Honeypot Systems

Honeypots have been largely used to capture and investigate malicious behavior through deliberately sacrificing their own resources in order to be attacked. Hybrid honeypot architectures consisting of frontends and backends are widely used in the research area, specially due to the benefits of their high scalability and fidelity for detailed attacking data collection. A hybrid honeypot system often needs a facility aimed to tightly control the network traffic, for purposes such as redirecting the traffic from the frontends to the backends for in-depth attack analysis. However, the current traffic redirection approaches, particularly the TCP connection handover mechanisms, are not stealthy and they can be easily detected by attackers.This paper proposes an SDN based network data controller for hybrid honeypot systems that uses a transparent TCP connection handover mechanism and provides a traffic filtering approach based on the Snort alert functionality. The controller is implemented as an application based on the open-source Ryu SDN framework. It allows the users to configure their own network data control rules, which based on the Snort alert messages will forward or redirect the traffic to the corresponding honeypots. The experiments validate the proposed mechanism and the testing results show that the controller can efficiently perform the stealthy TCP connection handover as well

Electronic band gaps and transport properties in periodically alternating mono- and bi-layer graphene superlattices

We investigate the electronic band structure and transport properties of periodically alternating mono- and bi-layer graphene superlattices (MBLG SLs). In such MBLG SLs, there exists a zero-averaged wave vector (zero-$\overline{k}$) gap that is insensitive to the lattice constant. This zero-$\overline{k}$ gap can be controlled by changing both the ratio of the potential widths and the interlayer coupling coefficient of the bilayer graphene. We also show that there exist extra Dirac points; the conditions for these extra Dirac points are presented analytically. Lastly, we demonstrate that the electronic transport properties and the energy gap of the first two bands in MBLG SLs are tunable through adjustment of the interlayer coupling and the width ratio of the periodic mono- and bi-layer graphene.Comment: More discussion is added and the English is polished. Accepted for publication in EP

Versatile virtual honeynet management framework

Honeypots are designed to investigate malicious behavior. Each type of homogeneous honeypot system has its own characteristics in respect of specific security functionality, and also suffers functional drawbacks that restrict its application scenario. In practical scenarios, therefore, security researchers always need to apply heterogeneous honeypots to cope with different attacks. However, there is a lack of general tools or platforms that can support versatile honeynet deployment in order to investigate the malicious behavior. In this study, the authors propose a versatile virtual honeynet management tool to address this problem. It is a flexible tool that offers security researchers the versatility to deploy various types of honeypots. It can also generate and manage the virtual honeynet through a dynamic configuration approach adapting to the mutable network environment. The experimental results demonstrate that this tool is effective to perform automated honeynet deployment toward a variety of heterogeneous honeypots

Three-state disk model for high quality and energy efficient streaming media servers

Energy conservation and emission reduction is an increasingly prominent and global issue in green computing. Among the various components of a streaming media server, the storage system is the biggest power consumer. In this paper, a Three-State Disk Model (3SDM) is proposed to conserve energy for streaming media servers without losing quality. According to the load threshold, the disks are dynamically divided into three states: overload, normal and standby. With the requests arriving and departing, the disk state transition among these three states. The purpose of 3SDM is to skew the load among the disks to achieve high quality and energy efficiency for streaming media applications. The load of disks in overload state will move to disks in normal state to improve the quality of service (QoS) level. The load of disks in normal state will be packed together to switch some disks into standby state to save energy. The key problem here is to identify the blocks that need migrating among disks. A sliding window replacement (SWR) algorithm is developed for this purpose, which calculates the block weight based on the request frequency falling within the window of a block. Employing a validated simulator, this paper evaluates the SWR algorithm for conventional disks based on the proposed 3SDM model. The results show that this scheme is able to yield energy efficient streaming media servers

Social Engineering: I-E based Model of Human Weakness for Attack and Defense Investigations

Social engineering is the attack aimed to manipulate dupe to divulge sensitive information or take actions to help the adversary bypass the secure perimeter in front of the information-related resources so that the attacking goals can be completed. Though there are a number of security tools, such as firewalls and intrusion detection systems which are used to protect machines from being attacked, widely accepted mechanism to prevent dupe from fraud is lacking. However, the human element is often the weakest link of an information security chain, especially, in a human-centered environment. In this paper, we reveal that the human psychological weaknesses result in the main vulnerabilities that can be exploited by social engineering attacks. Also, we capture two essential levels, internal characteristics of human nature and external circumstance influences, to explore the root cause of the human weaknesses. We unveil that the internal characteristics of human nature can be converted into weaknesses by external circumstance influences. So, we propose the I-E based model of human weakness for social engineering investigation. Based on this model, we analyzed the vulnerabilities exploited by different techniques of social engineering, and also, we conclude several defense approaches to fix the human weaknesses. This work can help the security researchers to gain insights into social engineering from a different perspective, and in particular, enhance the current and future research on social engineering defense mechanisms

Bifurcation Analysis and Chaos Control in a Discrete Epidemic System

The dynamics of discrete SI epidemic model, which has been obtained by the forward Euler scheme, is investigated in detail. By using the center manifold theorem and bifurcation theorem in the interior R+2, the specific conditions for the existence of flip bifurcation and Neimark-Sacker bifurcation have been derived. Numerical simulation not only presents our theoretical analysis but also exhibits rich and complex dynamical behavior existing in the case of the windows of period-1, period-3, period-5, period-6, period-7, period-9, period-11, period-15, period-19, period-23, period-34, period-42, and period-53 orbits. Meanwhile, there appears the cascade of period-doubling 2, 4, 8 bifurcation and chaos sets from the fixed point. These results show the discrete model has more richer dynamics compared with the continuous model. The computations of the largest Lyapunov exponents more than 0 confirm the chaotic behaviors of the system x→x+δ[rN(1-N/K)-βxy/N-(μ+m)x], y→y+δ[βxy/N-(μ+d)y]. Specifically, the chaotic orbits at an unstable fixed point are stabilized by using the feedback control method