Energy-efficient pipelined bloom filters for network intrusion detection

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Increasing the power efficiency of Bloom filters for network string matching

Although software based techniques are widely accepted in computer security systems, there is a growing interest to utilize hardware opportunities in order to compensate for the network bandwidth increases. Recently, hardware based virus protection systems have started to emerge. These type of hardware systems work by identifying the malicious content and removing it from the network streams. In principle, they make use of string matching. Bit by bit, they compare the virus signatures with the bit strings in the network. The Bloom filters are ideal data structures for string matching. Nonetheless, they consume large power when many of them used in parallel to match different virus signatures. In this paper, we propose a new type of Bloom filter architecture which exploits well-known pipelining technique. © 2006 IEEE

Low-power bloom filter architecture for deep packet inspection

Bloom filters are frequently used to identify malicious content like viruses in high speed networks. However, architectures proposed to implement Bloom filters are not power efficient. In this letter, we propose a new Bloom filter architecture that exploits the well-known pipelining technique. Through power analysis we show that pipelining can reduce the power consumption of Bloom filters up to 90%, which leads to the energy-efficient implementation of intrusion detection systems. © 2006 IEEE

Cosmological backreaction of a quantized massless scalar field

We consider the backreaction problem of a quantized minimally coupled massless scalar field in cosmology. The adiabatically regularized stress-energy tensor in a general Friedmann-Robertson-Walker background is approximately evaluated by using the fact that subhorizon modes evolve adiabatically and superhorizon modes are frozen. The vacuum energy density is verified to obey a new first order differential equation depending on a dimensionless parameter of order unity, which calibrates subhorizon/superhorizon division. We check the validity of the approximation by calculating the corresponding vacuum energy densities in fixed backgrounds, which are shown to agree with the known results in de Sitter space and space-times undergoing power law expansions. We then apply our findings to slow-roll inflationary models. Although backreaction effects are found to be negligible during the near exponential expansion, the vacuum energy density generated during this period might be important at later stages since it decreases slower than radiation or dust.Comment: 20 pages, 2 figures, v2: comments and a reference added, to appear in JCA

Individual Attitudes towards the Impact of Multinational Enterprises on Local Businesses

Individual attitudes towards multinational enterprises (MNEs) remains relatively understudied compared to individual attitudes towards other dimensions of globalization, particularly trade and immigration. In order to illuminate individual attitudes towards MNEs, this paper utilizes a large cross-country dataset (2003 International Social Survey Program) to examine individual perspectives on the impact of MNEs on local businesses. The paper draws on literature that studies the economic impacts of MNEs on local businesses, such as the transfer of technology from foreign affiliates to local businesses. Based on this literature the paper tests hypotheses to analyze how individuals’ skill-level (reflected in their educational attainment and occupational group) and the sector in which they work affects their perceptions of MNEs’ impact on local businesses. Conforming to expectations from the literature, the paper finds that highly skilled individuals who are senior-level managers, legislators, and officials are less likely to think MNEs are damaging local businesses. Also, private sector employees are less likely than public sector employees to see MNEs’ impact on local businesses as negative. The paper also finds variation in these attitudes across developed countries, developing countries, and formerly communist states in Central and Eastern Europe. In order to explore non-economic determinants of individual attitudes towards MNEs, the paper additionally explores how feelings of nationalism, confidence in democracy, and attitudes towards international affairs affect individual perspectives on MNEs. The paper additionally shows that retired citizens’ previous sector of employment and occupation influences their perception of the MNEs’ impact on local businesses and that type of FDI (M&A versus Greenfield investment) influences individual attitudes towards the impact of MNEs on local businesses.

Vibrating Winding Branes, Wrapping Democracy and Stabilization of Extra Dimensions in Dilaton Gravity

We show that, in the context of dilaton gravity, a recently proposed democratic principle for intersection possibilities of branes winding around extra dimensions yield stabilization, even with the inclusion of momentum modes of the wrapped branes on top of the winding modes. The constraints for stabilization massaged by string theory inputs forces the number of observed dimensions to be three. We also discuss consequences of adding ordinary matter living in the observed dimensions.Comment: Added a section discussing the linear and non-linear stability of the equilibrium point of the scale factors of the extra dimensions. Corrected a typo in the original field equations and other typos. Added and changed references. Final version appeared in JHE

Modeling toothpaste brand choice: An empirical comparison of artificial neural networks and multinomial probit model

Copyright @ 2010 Atlantis PressThe purpose of this study is to compare the performances of Artificial Neural Networks (ANN) and Multinomial Probit (MNP) approaches in modeling the choice decision within fast moving consumer goods sector. To do this, based on 2597 toothpaste purchases of a panel sample of 404 households, choice models are built and their performances are compared on the 861 purchases of a test sample of 135 households. Results show that ANN's predictions are better while MNP is useful in providing marketing insight

Adaptive Light Control System

An adaptive traffic light system for crossroads is to be developed with the control being the data obtained through fixed cameras attached to the light system. The control itself is to be adaptive as there is no need for collecting data during the time when there is no traffic at all. Thus the problem is to collect data adaptively and control the light system accordingly. The idea, of course, is not to have people wait for unnecessary amount of time along the way, while there is no traffic across roads. Though looks rather reasonable, a very good adaptive strategy and an accompanying algorithm need to be developed. The study group is asked for such an algorithm

Stabilization of Extra Dimensions and The Dimensionality of the Observed Space

We present a simple model for the late time stabilization of extra dimensions. The basic idea is that brane solutions wrapped around extra dimensions, which is allowed by string theory, will resist expansion due to their winding mode. The momentum modes in principle work in the opposite way. It is this interplay that leads to dynamical stabilization. We use the idea of democratic wrapping \cite{art5}-\cite{art6}, where in a given decimation of extra dimensions, all possible winding cases are considered. To simplify the study further we assumed a symmetric decimation in which the total number of extra dimensions is taken to be $Np$ where N can be called the order of the decimation. We also assumed that extra dimensions all have the topology of tori. We show that with these rather conservative assumptions, there exists solutions to the field equations in which the extra dimensions are stabilized and that the conditions do not depend on $p$. This fact means that there exists at least one solution to the asymmetric decimation case. If we denote the number of observed space dimensions (excluding time) by $m$, the condition for stabilization is $m\geq 3$ for pure Einstein gravity and $m\leq 3$ for dilaton gravity massaged by string theory parameters.Comment: Final versio