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Electronic article surveillance (EAS) is widely used in shops and libraries together with an RF-tag attached to the goods or books in order to prevent shoplifting. By implementing the addition of a moisture sensor to the RF-tag, other functions become possible, including the ability to use as an alarm with regards to frozen goods, which have been shipped but which have melted and have, subsequently, refrozen. In- relation to care for the elderly, one time-consuming step involves checking whether there is the necessity for a change of diaper and this can, instead, be based on an RF-tag with an EAS-system alarm. A preliminary investigation was made using the moisture sensors, which involved how the resistance changes when liquid and/or heat is applied. A simulation of the LCCR circuit (RF-tag with the sensor) was conducted in order to determine how the resonance frequency changes for different resistances levels. When the moisture sensors are applied to the RF-tag with the correct resistance no alarm will be triggered, but will be triggered when water is added to the moisture sensor. In order for the tag to be able to induce energy from the transmitter in the EAS-system the resistance must be less than ten ohms in relation to the entire tag. Results show that the implementation of the sensor on the RF-tag is possible and that it works in a satisfactory manner. / Elektroniska varularm EAS (Electronic article surveillance) är vida använt i butiker och bibliotek tillsammans med RF-tagg som är fäst på varor böcker för att förhindra snatteri. Genom att implementera fuktsensor till RF-taggen kan den få andra funktioner som då kan användas till larm om frysvaror fraktas har tinat men fryst igen, samt till äldrevården där ett tidsdödande moment är att hela tiden kontrollera om vårdtagaren behöver byta blöja. I stället kan RF-taggen med EAS-systemet larma. Förundersökning gjordes med fuktsensorn som är en sensor för hur resistansen ändras när vätska och värme förs på den. Simulering av LCCR krets (RF-tagg med sensor) gjordes för att se hur resonansfrekvensen ändras vid olika resistansnivåer. När fuktsensorn är applicerad på RF-tagg med rätt resistans triggas inte alarm, men däremot när vatten förs på fuktsensorn. För att taggen ska kunna inducera energin från sändaren i EAS-system måste resistansen vara lägre än tio ohm på hela RF-taggen. Resultatet visar att implementering av sensor på RF-tagg är möjlig och fungerar.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1993. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

The Internet has become a core component of our lives and businesses. Its reliability and availability are of paramount importance. There are many types of malware that impact the availability of the Internet, including network worms, bot-nets, viruses, etc. Detecting such attacks is a critical component of defending against them. This dissertation focuses on detecting and understanding self-propagating network worms, a type of malware with a proven record of disrupting the Internet. According to

In less than two decades, destruction and abuse caused by computer viruses and worms have grown from an anomaly to an everyday occurrence. In recent years, the Computer Emergency Response Team (CERT) has recorded a steady increase in software defects and vulnerabilities, similar to those exploited by the Slammer and Code Red worms. In response to such a threat, the academic community has started a set of research projects seeking to understand worm behavior through creation of highly theoretical and generalized models. Staniford et. al. created a model to explain the propagation behaviors of such worms in computer network environments. Their model makes use of the Kermack-McKendrick biological model of propagation as applied to digital systems. Liljenstam et. al. add a spatial perspective to this model, varying the infection rate by the scanning worms' source and destination groups. These models have been shown to describe generic Internet-scale behavior. However, they are lacking from a localized (campus-scale) network perspective. We make the claim that certain real-world constraints, such as bandwidth and heterogeneity of hosts, affect the propagation of worms and thus should not be ignored when creating models for analysis. In setting up a testing environment for this hypothesis, we have identified areas that need further work in the computer worm research community. These include availability of real-world data, a generalized and behaviorally complete worm model, and packet-based simulations. The major contributions of this thesis involve a parameterized, algorithmic worm model, an openly available worm simulation package (based on SSFNet and SSF.App.Worm), analysis of test results showing justification to our claim, and suggested future directions.

MSc (Applied Mathematics)) / Department of Mathematics and Applied Mathematics

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No description available.

In this study, branchiobdellids were collected from crayfish captured from two adjacent sites in Denton County, Texas. Identification of the branchiobdellid, Cambarincola vitrea Ellis, was first made and then work was extended to include several topics of ecological interest.

Vermicomposting is a possible method for reducing the amount of landfilled bio- waste. The product of vermicomposting is called worm tea. The thesis deals with the issue of composition and possible usage of worm tea, which is a liquid product of vermicomposting. The aim was to assess the composition and properties of worm tea samples provided from households. Then a mixed sample was tested as a nutrient solution for hydroponic growing. One year operation of a small vermicomposter as a mean of community bio-waste disposal was also assessed in the thesis. Conductivity, pH, content of selected cations and anions and TOC were determined for each worm tea sample. Values of conductivity were then assessed by a correlation test with inhibition values gained from an ecotoxicological test with Sinapis alba. Testing of worm tea as a nutrient solution was done in an opened hydroponic system with Lactuca sativa seedlings. Results show that samples of worm tea are very different and they can not be watered down according to their conductivity as was hypothesised. The largest percentage of samples evinced stimulating qualities in a concentration of 2,5 %. Worm tea can be used as an alternative of nutrient solution for hydroponic growth and it has potential for utilization as an stimulant for germination and...