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IEEE 802.11 (WiFi) only has two modes of trust--complete trust or complete untrust. The lack of nuance leaves no room for sensors that a user does not fully trust, but wants to connect to their network, such as a WiFi sensor. Solutions exist, but they require advanced knowledge of network administration. We solve this problem by introducing a new way of modulating data in the latency of the network, called Latency Shift Keying. We use specific characteristics of the WiFi protocol to carefully control the latency of just one device on the network. We build a transmitter, receiver, and modulation scheme that is designed to encode data in the latency of a network. We develop an application, Wicket, that solves the WiFi trust issue using Latency Shift Keying to create a new security association between an untrusted WiFi sensor and a wired device on the trusted network. We evaluate its performance and show that it works in many network conditions and environments.

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Atenção refere-se ao conjunto de processos que leva à seleção ou processamento preferencial de informações presentes em determinadas porções da rede nervosa. Existem relatos de que músicos exibem melhor desempenho que não-músicos em tarefas que envolvem atenção dado que a tarefa de leitura à primeira vista (de partituras) ativa múltiplas regiões encefálicas, entre elas, áreas envolvidas na orientação da atenção. O presente estudo investigou a orientação encoberta da atenção em músicos capazes de realizar leitura à primeira vista. Investigou ainda, se a continuidade do estudo formal de música ao longo de três anos, depois do ingresso na Universidade (ECA - Escola de Música) produz alterações significativas na memória operacional, avaliada por meio do teste 2-back, em relação a não-músicos que também ingressaram na Universidade, porém em área distinta (Biologia, IB-USP) que não envolve música. Os resultados no teste de atenção encoberta mostraram que não-músicos exibem assimetrias na orientação da atenção visuo-espacial; seu tempo de reação para estímulos apresentados no hemicampo direito é significantemente menor que o observado para estímulos apresentados no hemicampo esquerdo. Ademais, não-músicos exibem efeito de validade apenas para estímulos-alvo apresentados no hemicampo direito. Em músicos, não houve diferenças significantes nos tempos de reação a estímulos apresentados nos hemicampos direito e esquerdo; esses tempos foram significantemente menores que os exibidos pelos não-músicos, para estímulos apresentados no hemicampo esquerdo. Não obstante essa diferença, os músicos também exibiram efeito de validade apenas para estímulos-alvo apresentados no hemicampo direito. Não houve diferenças significantes de desempenho entre músicos e não-músicos no teste de memória operacional. Assim, o estudo formal de música parece relacionar-se com alterações nos processos de orientação da atenção. / Attention corresponds to selection or preferential processing of information maintained in certain portions of the neural network. Musicians seem to exhibit better performance relative to non-musicians in attention-dependent tasks, which is ascribed to sight-reading of scores that activates multiple brain regions, including areas involved on orienting of attention. The present study investigated covert orienting of visual attention in people exposed to prolonged study of music, thus becoming capable of sight-reading. In addition, we investigated if continuation of formal music study after getting into the University (School of Music) leads to significant chance in working memory, as evaluated by the 2-back test involving letters, relative to non-musicians that also get into the University but in a distinct area (Biology). The results in the covert attention test showed that non-musicians exhibit an asymmetry in visuo-spatial orienting of attention; their reaction times for target-stimuli presented in the right hemifield were significantly smaller than those observed for stimuli presented in the left hemifield. In addition, non-musicians exhibited validity effect only for target-stimuli presented in the right hemifield. In contrast, musicians did not exhibit significant differences in reaction times for target stimuli presented in the left or right hemifields; however, these reaction times were smaller than those seen for non-musicians for stimuli presented in the left hemifield. Despite this difference, musicians also exhibited an asymmetry, that is, their validity effect was also restricted to target stimuli presented in the right hemifield. Musicians and non-musicians did not differ in the working memory test. Together, these results indicate that formal music study relates with changes in the processes of orienting of attention.

Disrupting terrorist and other covert networks requires identifying and capturing key leaders. Previous research by Martonosi et al. (2009) defines a load metric on vertices of a covert network representing the amount of communication in which a vertex is expected to participate. They suggest that the visibility of a target vertex can be increased by removing other, more accessible members of the network. This report evaluates the feasibility of efficiently calculating the optimal subset of vertices to remove. We begin by proving that the general problem of identifying the optimally load maximizing vertex set removal is NP-complete. We then consider the feasibility of more quickly computing the load maximizing single vertex removal by designing an efficient algorithm for recomputing Gomory- Hu trees. This leads to a result regarding the uniqueness of Gomory- Hu trees with implications towards the feasibility of one approach for Gomory- Hu tree reconstruction. Finally, we propose a warm start algorithm which performs this reconstruction, and analyze its runtime experimentally.

<p><p>The languages of the world are constantly changing and slang intrudes the vocabulary of many people all over the world. But what is slang and where does it come from? Are there differences in the slang that men and women use? And what is the point of using slang? It seems that the slang that was used by previous generations has either gone out of use or has now become a part of accepted standard language; basically, the youth of today reject the slang that their parents used. This would indicate that it is not “cool” to use the same slang as one’s parents did and to avoid this, new slang is invented to replace old slang aiding the youth of today to be able to be shocking or amusing by speaking in a certain way.</p></p><p><p><p>In this essay the focus lies on the slang of British English and this is investigated by an analysis of a contemporary film and a TV-show to see how common the use of slang is in these kinds of medias. The intention is also too see if slang differs according to gender and in what different areas slang is used.</p><p>The film “Football factory” and the TV-show “Little Britain” were closely watched and all slang was noted down and categorized in terms of users and areas of use. To make this easier and to make sure not to lose any parts of the dialogues scripts were found on the internet and used as aids when analyzing. “Football factory” is a movie about British football hooligans which is a very male-dominated world. “Little Britain” is a TV-show consisting of many small sketches with very different characters of both genders but mostly played by male actors.</p></p><p><p>The results were somewhat surprising as the expectation was to find some slang in the chosen material but the amount of slang use exceeded the expectations. Slang seems to besomething that people use in many different areas of use, such as, when talking about sex,drugs or other things that might be taboo. It seems that slang is a big part of the language thatboth men and women use. However, in the material used for this study, young men were theones who used slang the most.</p></p></p>

We argue that there is a crucial difference between determiner and adverbial quantification. Following Herburger [2000] and von Fintel [1994], we assume that determiner quantifiers quantify over individuals and adverbial quantifiers over eventualities. While it is usually assumed that the semantics of sentences with determiner quantifiers and those with adverbial quantifiers basically come out the same, we will show by way of new data that quantification over events is more restricted than quantification over individuals. This is because eventualities in contrast to individuals have to be located in time which is done using contextual information according to a pragmatic resolution strategy. If the contextual information and the tense information given in the respective sentence contradict each other, the sentence is uninterpretable. We conclude that this is the reason why in these cases adverbial quantification, i.e. quantification over eventualities, is impossible whereas quantification over individuals is fine.

Fixational eye movements occur involuntarily during visual fixation of stationary scenes. The fastest components of these miniature eye movements are microsaccades, which can be observed about once per second. Recent studies demonstrated that microsaccades are linked to covert shifts of visual attention [e.g., Engbert & Kliegl (2003), Vision Res 43:1035-1045]. Here,we generalized this finding in two ways. First, we used peripheral cues, rather than the centrally presented cues of earlier studies. Second, we spatially cued attention in vision and audition to visual and auditory targets. An analysis of microsaccade responses revealed an equivalent impact of visual and auditory cues on microsaccade-rate signature (i.e., an initial inhibition followed by an overshoot and a final return to the pre-cue baseline rate). With visual cues or visual targets,microsaccades were briefly aligned with cue direction and then opposite to cue direction during the overshoot epoch, probably as a result of an inhibition of an automatic saccade to the peripheral cue. With left auditory cues and auditory targets microsaccades oriented in cue direction. Thus, microsaccades can be used to study crossmodal integration of sensory information and to map the time course of saccade preparation during covert shifts of visual and auditory attention.

This thesis presents the establishment of a covert-channel in wireless networks in the form of frames with intentionally corrupted Frame Check Sequences (FCSs). Previous works had alluded to the possibility of using this kind of covert-channel as an attack vector. We modify a simulation tool, called Sinalgo, which is used as a test bed for generating hypothetical scenarios for establishing a covert-channel. Single and Multi-Agent systems have been proposed as behaviour-based intrusion detection mechanisms, which utilize statistical information about network traffic. This utilized statistical information is used to detect covert-channel communications. This work highlights the potential impact of having this attack perpetrated in communications equipment with a low chance of being detected, if properly crafted. / UOIT

Covert channels are becoming more popular as security risks grow in networks. One area that is promising for covert channels is wireless networks, since many use a collision avoidance scheme such as carrier sense multiple access with collision avoidance (CSMA/CA). These schemes often introduce randomness in the network, which provides good cover for a covert timing channel. In this thesis, we use the 802.11 standard as an example to demonstrate a wireless covert channel. In particular, most 802.11 configurations use a distributed coordinated function (DCF) to assist in communications. This DCF uses a random backoff to avoid collisions, which provides the cover for our covert channel. Our timing channel provides great improvements on other recent covert channels in the field of throughput, while maintaining high accuracy. We are able to achieve throughput over 8000 bps using Covert DCF, or by accepting a throughput of 1800 bps we can achieve higher covertness and 99% accuracy as well.