Intrusion detection in MANET using classification algorithms: The effects of cost and model selection

Intrusion detection is frequently used as a second line of defense in Mobile Ad-hoc Networks (MANETs). In this paper we examine how to properly use classification methods in intrusion detection for MANETs. In order to do so we evaluate five supervised classification algorithms for intrusion detection on a number of metrics. We measure their performance on a dataset, described in this paper, which includes varied traffic conditions and mobility patterns for multiple attacks. One of our goals is to investigate how classification performance depends on the problem cost matrix. Consequently, we examine how the use of uniform versusweighted cost matrices affects classifier performance. A second goal is to examine techniques for tuning classifiers when unknown attack subtypes are expected during testing. Frequently, when classifiers are tuned using cross-validation, data from the same types of attacks are available in all folds. This differs from real-world employment where unknown types of attacks may be present. Consequently, we develop a sequential cross-validation procedure so that not all types of attacks will necessarily be present across all folds, in the hope that this would make the tuning of classifiers more robust. Our results indicate that weighted cost matrices can be used effectively with most statistical classifiers and that sequential cross-validation can have a small, but significant effect for certain types of classifiers.     

Restaurierung antiker Tempel: Experimentelle Untersuchungen zum Ausziehverhalten von Verankerungen im Marmor

Restoration of antique temples: Experimental investigations on the pull‐out behaviour of anchors in marble. In restoration works of antique Greek temples individual marble blocks are connected together to form a single element, e.g. an architrave. Due to the demand of reversibility of the intervention, this is done in the Acropolis of Athens by means of titanium threaded bars that are inserted in the marble, in predrilled holes filled with cement mortar. This way of restoration corresponds to a partial rehabilitation of the architraves. This paper presents experimental investigations on the pull‐out behaviour of such anchors. The tests are performed in specially designed equipment. Failure takes place for all tests in the interface between the mortar and the marble. It has been shown that the form of the thread influences considerably the carrying capacity. Possible limit states are introduced.     

Tertiary fatty amides as diesel fuel substitutes

This paper presents experimental results regarding the impact of adding different tertiary amides of fatty acids to mineral diesel fuel; an assessment of the behaviour of these compounds as possible diesel fuel extenders is also included. Measurements of cetane number, cold flow properties (cloud point, pour point and CFPP), density, kinematic viscosity, flash point and distillation temperatures are reported, while initial experiments concerning the effects on particulate emissions are also described. Most of the examined tertiary fatty amides esters have very good performance and they can be easily prepared from fatty acids (biomass). Such compounds or their blends could be used as mineral diesel fuel or even fatty acid methylesters (FAME, biodiesel) substitutes or extenders. Copyright © 2000 John Wiley & Sons, Ltd.     

Impact of inflammation on anti‐oxidative effects of vitamin E‐coated membrane dialyzer in patients on chronic hemodialysis

Hemodialysis (HD) with the use of vitamin E‐coated membrane (VEM) dialyzers is shown to exert anti‐inflammatory and antioxidative effects in patients with end‐stage renal disease on HD. However, the association of baseline inflammatory status with the antioxidative effects of VEM has not been investigated thus far. Thirty‐five stable end‐stage renal disease patients treated with VEM for 6 months were enrolled in the present prospective, observational cohort study. For the previous 3 months minimum, 17 (48%) patients were dialyzed with a cellulose, eight (23%) patients with a hemophane, and 10 (29%) patients with a polysulfone 1.2 to 1.5 m² hollow fiber dialyzer. The effects of treatment on oxidized low‐density lipoprotein (oxLDL) were stratified according to half percentiles of baseline serum logC‐reactive protein and interleukin‐6, and the association between treatment goal, arbitrarily defined as a minimum 30% decrease in baseline oxLDL, was assessed with the use of logistic regression analysis. The higher C‐reactive protein and interleukin‐6 half percentiles were independently and additively associated with a higher odds ratio for achieving treatment goal. Adjustment for baseline oxLDL, age, sex, HD duration, smoking, and body mass index did not attenuate the odds ratios, whereas the history of diabetes, as primary renal disease, significantly decreased the odds ratio for achieving treatment goal. Increased baseline C‐reactive protein and interleukin‐6 are independent, additive factors associated with the effect of VEM on oxLDL in HD patients.     

Multiplayer online games as educational tools: Facing new challenges in learning

This paper outlines a proposal for the development of educational multiplayer online games based on the activity theory, as an alternative to the current trend in multiplayer gaming and a means of promoting collaboration among students. In order to examine whether online games are engaging for learners, we consider multiple factors regarding game play – such as frequency of game use, gender differences, identification with the characters, and game preferences – as well as some psychosocial factors that may influence learning – such as academic performance, self-esteem, and computer self-efficacy. This paper suggests that online multiplayer educational games should be approached as a complex learning system, based on the principles of activity theory, where the Subjects would interact with other Subjects, Objects and Tools of the game, under specified Rules and create Communities through division of labor, leading to the expected learning outcome. Thus, we suggest taking into account some important issues concerning the Subjects that the activity theory refers to, such as gender differences in playing games, academic performance, self-esteem and computer self-efficacy.     

Do liberalised electricity markets help or hinder CHP and district heating? The case of the UK

This paper investigates whether and how Danish-style combined heat and power (CHP) and district heating (DH) can be implemented in the UK in the context of a liberalised electricity market. There is currently an absence, in the UK, of the Danish system of planning rules and also good tariffs for CHP electricity exports to the grid that led to the development of the Danish system of CHP and DH. However, there are some changes in UK planning practice that may help CHP and DH. These would need to be strengthened, but it is also the case that the way the liberalised electricity market operates in the UK effectively discriminates against small CHP plant selling their electricity to the grid. A Danish system of ‘aggregating’ CHP–DH plant using thermal stores could help to overcome this problem. However, an alternative strategy would be to establish feed-in tariffs for CHP units that are linked to DH modelled on the Danish ‘triple tariff’. This could help the UK's long-term objective of absorbing high levels of fluctuating renewable energy sources.     

Biotechnological conversions of biodiesel derived waste glycerol by yeast and fungal species

Fifteen eukaryotic microorganisms were tested for their ability to assimilate biodiesel derived waste glycerol and convert it into value-added metabolic products. For this purpose yeast and Zygomycetes strains were cultivated in nitrogen-limited raw glycerol-based media (initial glycerol concentration 30 g/L). Yeasts tested accumulated restricted lipid quantities (up to ∼22%, wt/wt, in the case of Rhodotorula sp), while differentiations in their fatty acid composition were recorded in relation to the yeast strains employed and the fermentation time. On the contrary, fungi accumulated higher quantities of lipid inside their mycelia (ranging between 18.1 and 42.6%, wt/wt, of dry biomass) that contained in variable amounts the medically important GLA (γ-linolenic acid). Moreover, Yarrowia lipolytica, Pichia membranifaciens and Thamnidium elegans were further studied in media having increased initial glycerol concentrations. In these conditions Y. lipolytica secreted significant amounts of acetic acid (29.2 g/L), as well as mannitol (19.4 g/L) while P. membranifaciens reached 28.4 g/L of biomass at glycerol concentration 90 g/L. T. elegans produced 11.6 g/L of oil, with 71.1%, wt/wt, of fat in biomass, while the maximum concentration of GLA was 371 mg/L. Detailed analysis of T. elegans lipids indicated that the phospholipids fraction was particularly rich in polyunsaturated fatty acids.     

Modelling of low temperature wine-making,using immobilized cells

A new biocatalyst was prepared by immobilization of Saccharomyces cerevisiae AXAZ-1 yeast cells on whole corn grains. This biocatalyst was used for 30 repeated batch fermentations of glucose and grape musts at various temperatures. The biocatalyst retained its operational stability for a long period and it proved able to produce dry wines of fine clarity, even at extremely low temperatures (5 °C). The produced wines were analyzed for volatile byproducts by GC and GC–MS. The results showed an increase in the number and amount of esters produced when immobilized cells were used. In addition, an increase in the percentages of esters and a decrease in those of alcohols with the decrease of fermentation temperature were observed. Finally a model, appropriate for describing sugar consumption and the simultaneous ethanol formation by immobilized cells, was proposed. The results of this model fit almost perfectly with the experimental data.     

Classifying RFID attacks and defenses

RFID (Radio Frequency Identification) systems are one of the most pervasive computing technologies with technical potential and profitable opportunities in a diverse area of applications. Among their advantages is included their low cost and their broad applicability. However, they also present a number of inherent vulnerabilities. This paper develops a structural methodology for risks that RFID networks face by developing a classification of RFID attacks, presenting their important features, and discussing possible countermeasures. The goal of the paper is to categorize the existing weaknesses of RFID communication so that a better understanding of RFID attacks can be achieved and subsequently more efficient and effective algorithms, techniques and procedures to combat these attacks may be developed.     

Assessing allergenicity of different tomato ecotypes by using pooled sera of allergic subjects: identification of the main allergens

An evaluation of the potential allergenicity of different tomato ecotypes is reported. Twelve tomato ecotypes were assessed through a proteomic approach, using pools of sera of allergic patients from two different regions (Emilia Romagna in Northern Italy and Campania in Southern Italy), in order to identify the major allergens and evaluate differences in IgE binding properties of the tomato cultivars. Pooled sera of allergic people from Emilia Romagna showed as the main allergen a suberization-associated anionic peroxidase, whereas pooled sera of allergic patients from Campania were mostly reactive to profilin. The two proteins were identified through a proteomic approach based on the use of high-resolution mass spectrometric techniques. Quite interestingly, in some cases, several ecotypes showed a less reactivity toward patients?? sera than other, potentially indicating the possibility to identify ipoallergenic varieties. Anyway, the allergenic pattern response to tomatoes was serum-specific, indicating that the allergenic properties of different tomato ecotypes are defined by the specific proteins to which the patient is sensitized, a strong indication that ipoallergenicity of the different ecotypes is possible, but mostly related to the individual susceptibility.