Dirt Jumper: A New and Fast Evolving Botnet-for-DDoS

Abstract-In July 2011, a fairly new and rather aggressive strain of botnet-for-DDoS malware, named Dirt Jumper, was identified by Arbor Networks. Since then, numerous incidents of DDoS attacks involving this strain of malware have been reported. In this paper, we first give a general overview of Dirt Jumper's history, structure and operation as it has been documented on the Internet. Subsequently, we present the results of our own analysis of Dirt Jumper, conducted using the GFI Sandbox environment. We also provide an overview of Pandora DDoS toolkit -the latest offspring coming out of the Dirt Jumper family, which appeared on the black botnet marked in the early 2012. We conclude the paper by outlining some areas of continuing and future work

Creating loops with value recovery: empirical study of fresh food supply chains

Centre for Irish Business and Economic Performance, Queen’s University Belfast (QUB) under grant for the project: “Waste Not, Want Not: Contributing to a Sustainable Food Industry by Managing Food Waste

The metallicity gradient as a tracer of history and structure : the Magellanic Clouds and M33 galaxies

Original article can be found at: http://www.aanda.org/ Copyright The European Southern Observatory (ESO) DOI: 10.1051/0004-6361/200912138Context. The stellar metallicity and its gradient place constraints on the formation and evolution of galaxies. Aims. This is a study of the metallicity gradient of the LMC, SMC and M33 galaxies derived from their asymptotic giant branch (AGB) stars. Methods. The [Fe/H] abundance was derived from the ratio between C- and M-type AGB stars and its variation analysed as a function of galactocentric distance. Galaxy structure parameters were adopted from the literature. Results. The metallicity of the LMC decreases linearly as −0.047±0.003 dex kpc−1 out to ∼8 kpc from the centre. In the SMC, [Fe/H] has a constant value of ∼−1.25 ± 0.01 dex up to ∼12 kpc. The gradient of the M33 disc, until ∼9 kpc, is −0.078 ± 0.003 dex kpc−1 while the outer disc/halo, out to ∼25 kpc, has [Fe/H] ∼ −1.7 dex. Conclusions. The metallicity of the LMC, as traced by different populations, bears the signature of two major star forming episodes: the first one constituting a thick disc/halo population and the second one a thin disc and bar due to a close encounter with the Milky Way and SMC. The [Fe/H] of the recent episode supports an LMC origin for the Stream. The metallicity of the SMC supports star formation, ∼3 Gyr ago, as triggered by LMC interaction and sustained by the bar in the outer region of the galaxy. The SMC [Fe/H] agrees with the present-day abundance in the Bridge and shows no significant gradient. The metallicity of M33 supports an “insideout” disc formation via accretion of metal poor gas from the interstellar medium.Peer reviewe

Drillstring-borehole interaction: backward whirl instabilities and axial loading

A major concern within the oil drilling industry remains the interaction between the drillstring and borehole. The interaction between the drillstring and borehole wall involves nonlinearities in the form of friction and contact. The drillstring borehole interaction induces whirling behaviour of the drillstring causing forward whirl, backward whirl or intermittent bouncing behaviour depending on the system parameters. The purpose of this study is to analyse the steady backward whirl behaviour within the system which reduces the fatigue life of the drillstring. Initially a two discs model was developed to analyse the behaviour of the system. The theoretical model was tuned by altering the phase of the eccentric mass. This excites each lateral modes of the system in isolation. The effects of impact, friction and mass unbalance are included in the model. For the tuned system the backward whirl behaviour was analysed by carrying out a rotor speed sweep spanning the lateral natural frequencies. The influence of rotor speed on the system dynamics is explored using a run up and run down and is analysed using a waterfall plot. The waterfall plot indicated the frequency of maximum response corresponding to each rotor speed. Depending on the whirling behaviour the dominant frequency was observed at the lateral natural frequency, the rotational speed or the backward whirl frequency. The influence of variation in whirling behaviour due to altering of the axial load was analysed for a multiple disc case consisting of five discs. A transition in behaviour along the length of the drillstring was observed due to the axial load and bending moment interactions. Depending on the mode excited impact and sustained contact initiation with the borehole varied across the different stabilizer locations

Saving Energy and Improving Communications using Cooperative Group-based Wireless Sensor Networks

Wireless Sensor Networks (WSNs) can be used in many real applications (environmental monitoring, habitat monitoring, health, etc.). The energy consumption of each sensor should be as lower as possible, and methods for grouping nodes can improve the network performance. In this work, we show how organizing sensors in cooperative groups can reduce the global energy consumption of the WSN. We will also show that a cooperative group-based network reduces the number of the messages transmitted inside the WSNs, which implieasa reduction of energy consumed by the whole network, and, consequently, an increase of the network lifetime. The simulations will show how the number of groups improves the network performance. © 2011 Springer Science+Business Media, LLC.García Pineda, M.; Sendra Compte, S.; Lloret, J.; Canovas Solbes, A. (2013). Saving Energy and Improving Communications using Cooperative Group-based Wireless Sensor Networks. Telecommunication Systems. 52(4):2489-2502. doi:10.1007/s11235-011-9568-3S24892502524Akyildiz, I. F., Su, W., Sankarasubramaniam, Y., & Cayirci, E. (2002). Wireless sensor networks: a survey. Journal of Computer Networks, 38(4), 393–422.Garcia, M., Bri, D., Sendra, S., & Lloret, J. (2010). Practical deployments of wireless sensor networks: a survey. Journal on Advances in Networks and Services, 3(1&2), 1–16.Lloret, J., Garcia, M., Bri, D., & Sendra, S. (2009). A wireless sensor network deployment for rural and forest fire detection and verification. Sensors, 9(11), 8722–8747.Mainwaring, A., Polastre, J., Szewczyk, R., & Culler, D. (2002). Wireless sensor networks for habitat monitoring. In ACM workshop on sensor networks and applications (WSNA’02), Atlanta, GA, USA, September.Garcia, M., Sendra, S., Lloret, G., & Lloret, J. (2010, in press). Monitoring and control sensor system for fish feeding in marine fish farms. 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Dynamic power save techniques for next generation WLAN systems. In Proceedings of the 38th southeastern symposium on system theory (SSST), Cookeville, Tennessee, USA, 5–7 March.Raghunathan, V., Schurgers, C., Park, S., & Srivastava, M. (2002). Energy aware wireless microsensor networks. IEEE Signal Processing Magazine, 19(2), 40–50.Min, R., Bhardwaj, M., Cho, S.-H., Shih, E., Sinha, A., Wang, A., & Chandrakasan, A. (2001). Low power wireless sensor networks. In Proceedings of international conference on VLSI design, India, Bangalore, 3–7 January.Salhieh, A., Weinmann, J., Kochha, M., & Schwiebert, L. (2001). Power efficient topologies for wireless sensor networks. In Proceedings of the IEEE international conference on parallel processing (pp. 156–163), 3–7 September.Jayashree, S., Manoj, B. S., & Murthy, C. S. R. (2004). A battery aware medium access control (BAMAC) protocol for Ad-hoc wireless network. In Proceedings of the 15th IEEE international symposium on personal, indoor and mobile radio communications (PIMRC 2004), Barcelona, Spain, 5–8 September (Vol. 2, pp. 995–999).Ye, W., Heidemann, J., & Estrin, D. (2002). An energy-efficient MAC protocol for wireless sensor networks. In Proceedings IEEE INFOCOM 2002, the 21st annual joint conference of the IEEE computer and communications societies, New York, USA, 23–27 June.Ching, C., & Schindelhauer, C. (2010). Utilizing detours for energy conservation in mobile wireless networks. Journal of Telecommunication Systems. doi: 10.1007/s11235-009-9188-3 .Gao, Q., Blow, K., Holding, D., Marshall, I., & Peng, X. (2004). Radio range adjustment for energy efficient wireless sensor networks. Journal of Ad Hoc Networks, 4(1), 75–82.Li, D., Jia, X., & Liu, H. (2004). Energy efficient broadcast routing in static ad hoc wireless networks. IEEE Transactions on Mobile Computing, 3(1), 1–8.Camilo, T., Carreto, C., Silva, J., & Boavida, F. (2006). An energy-efficient ant-based routing algorithm for wireless sensor networks. In Lecture notes in computer science: Vol. 4150. Ant colony optimization and swarm intelligence (pp. 49–59). Berlin: Springer.Younis, M., Youssef, M., & Arisha, K. (2002). Energy-aware routing in cluster-based sensor networks. In Proceedings of the 10th IEEE international symposium on modeling, analysis, and simulation of computer and telecommunications systems (MASCOTS ’02) (pp. 129–136). Washington: IEEE Computer Society.Cheng, Z., Perillo, M., & Heinzelman, W. B. (2008). General network lifetime and cost models for evaluating sensor network deployment strategies. IEEE Transactions on Mobile Computing, 7(4), 484–497.Heo, N., & Varshney, P. K. (2005). Energy-efficient deployment of intelligent mobile sensor networks. IEEE Transactions on Systems, Man and Cybernetics Part A Systems and Humans, 35(1), 78–92.Vlajic, N., & Xia, D. (2006). Wireless sensor networks: to cluster or not to cluster? 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The Abundance Gradient in the Extremely Faint Outer Disk of NGC 300

In an earlier work, we showed for the first time that the resolved stellar disk of NGC 300 is very extended with no evidence for truncation, a phenomenon that has since been observed in other disk galaxies. We revisit the outer disk of NGC 300 in order to determine the metallicity of the faint stellar population. With the Gemini Multi Object Spectrograph camera at Gemini South, we reach 50% completeness at (g′, i′) = (26.8-27.4, 26.1-27.0) in photometric conditions and 07 seeing. At these faint depths, careful consideration must be given to the background galaxy population. The mean colors of the outer disk stars fall within the spread of colors for the background galaxies, but the stellar density dominates the background galaxies by 2:1. The predominantly old stellar population in the outer disk exhibits a negative abundance gradient - as expected from models of galaxy evolution - out to about 10 kpc where the abundance trend changes sign. We present two scenarios to explain the flattening, or upturn, in the metallicity gradient of NGC 300 and discuss the implication this has for the broader picture of galaxy formation