A Survey on Botnet Attacks

Devices connected to the Internet are the target of numerous attacks to steal or exploit their resources. As these attacks become widespread (and sophisticated), the first step in protecting your organization is knowing exactly what you are facing. We currently have botnets that are the main source of network attacks such as spam, denial of service (DDoS), click fraud, data theft, Pass the Hash, and RDC attack. With the evolution of technology, we have several solutions to protect against attacks that undermine businesses, governments, individuals, but security attack methods are increasing daily. This study seeks further investigate botnet attacks and also provide a comparison of these attacks, lastly, the survey will create awareness for forthcoming botnet research endeavors

Population Redistribution among Multiple Electronic States of Molecular Nitrogen Ions in Strong Laser Fields

We carry out a combined theoretical and experimental investigation on the population distributions in the ground and excited states of tunnel ionized N2 molecules at various driver wavelengths in the near- and mid-infrared range. Our results reveal that efficient couplings (i.e., population exchanges) between the ground state and the excited states occur in strong laser fields. The couplings result in the population inversion between the ground and the excited states at the wavelengths near 800 nm, which is verified by our experiment by observing the amplification of a seed at ~391 nm. The result provides insight into the mechanism of free-space nitrogen ion lasers generated in remote air with strong femtosecond laser pulses.Comment: 18 pages, 4 figure

A general QoS aware flow-balancing and resource management scheme in distributed software-defined networks

Due to the limited service capabilities of centralized controllers, it is difficult to process high volume of flows within reasonable time. This particularly degrades the strict quality of service (QoS) requirements of interactive media applications, which is non-negligible factor. To alleviate this concern, distributed deployments of software-defined network (SDN) controllers are inevitable and have gained a predominant position. However, to maintain application specific QoS requirements, the number of resources used in network directly impacts the capital and operational expenditure. Hence, in distributed SDN architectures, issues such as flow arrival rate, resources required and operational cost have significant mutual dependencies on each other. Therefore, it is essential to research feasible methods to maintain QoS and minimize resources provisioning cost. Motivated from this, we propose a solution in a distributed SDN architectures that provides flow-balancing (with guaranteed QoS) in pro-active operations of SDN controllers, and attempts to optimize the use of instance resources provisioning costs. We validate our solution using the tools of queuing theory. Our studies indicate that with our solution, a network with minimum resources and affordable cost with guaranteed application QoS can be set-up

Three-peak evolution characteristics of supporting stress on a super-long working face in a thick coal seam

Increasing working face length is the development trend of intelligent and efficient longwall fully mechanized mining. By combining field measurement and theoretical calculation, change characteristics of the frequency, peak value, and range of weighting in a long working face in a 1000 m-deep shaft of Kouzidong Coal Mine (Fuyang City, Anhui Province, China) were studied. Based on the mechanical model of the hydraulic support group of the elastic independent support, force characteristics and posture change characteristics of the support in the 121304 working face of the mine were studied and analyzed. The supporting stress characteristics of the deep super-long working face were revealed, and the theoretical calculation was in good agreement with the actual measurement. Based on the aforementioned model, support parameters and control technology of the 140502 working face were studied. The results show that as the length of the working face increases, the supporting stress gradually transforms from a single peak to multiple peaks and expands to both ends of the working face. The weighting in different areas of the working face is characterized by an obvious time sequence and great difference in intensity. When the working face length is 300 m, the multi-peak characteristic of super-long working faces appears. The M-shaped three-peak characteristic can be used as the criterion for super-long working faces. A reasonable working face length should be determined by comprehensively considering occurrence conditions of coal seams, working face parameter, and equipment ability. According to the different attributes of hydraulic supports in space and function and combining with zonal characteristics of the long working face, the criterion for the super-long working face and the principle of zonal cooperative control of hydraulic support groups were revealed. In addition, a cooperative control method of equipment groups in the working face based on the state error and cost functions was put forward, and the three-level cooperative control strategy and implementation method were formulated. It can effectively guide the equipment group in the super-long fully mechanized working face in deep thick coal seams to achieve optimal coordinated control

Gender difference in knowledge of tuberculosis and associated health-care seeking behaviors: a cross-sectional study in a rural area of China

<p>Abstract</p> <p>Background</p> <p>Tuberculosis (TB) detection under the national TB control program in China follows passive case-finding guidelines, which could be influenced by the accessibility of health service and patient's health-care seeking behaviors. One intriguing topic is the correlation between men and women's knowledge on TB and their health-care seeking behaviors.</p> <p>Methods</p> <p>Two cross-sectional studies were separately carried out in Yangzhong County, a rural area of China. One study, by using systematic sampling method, including 1,200 subjects, was conducted to investigate the TB knowledge among general population. Another study in the same source population screened 33,549 people aged 15 years or over among 20 stratified cluster-sampled villages for identifying prolonged cough patients at households and individual interviews were then carried out. Gender difference in the knowledge of TB and health-care seeking behaviors was analyzed particularly.</p> <p>Results</p> <p>Among general population, only 16.0% (men 17.1% vs. women 15.0%) knew the prolonged cough with the duration of 3 weeks or longer was a symptom for suspicious TB. Fewer women than men knew the local appointed health facility for TB diagnosis and treatment as well as the current free TB service policy. Moreover, women were less likely to learn information about TB and share it with others on their own initiatives. On the contrary, after the onset of the prolonged cough, women (79.2%) were more likely to seek health-care than men (58.6%) did. However, a large part of women preferred to visit the lower level non-hospital health facilities at first such as village clinics and drugstores.</p> <p>Conclusion</p> <p>TB and DOTS program were not well known by rural Chinese. Gender issues should be considered to reduce diagnostic delay of TB and improve both men and women's access to qualified health facility for TB care. Strengthening awareness of TB and improving the accessibility of health-care service is essential in TB control strategy, especially under the current vertical TB control system.</p