Integrating secure mobile P2P systems and Wireless Sensor Networks

Aquesta tesi tracta de les diferents limitacions trobades a WSN per a habilitar-ne el desplegament en nous escenaris i facilitar la difusió de la informació obtinguda. A un nivell baix, ens centrem en el consum d'energia, mentre que, a un nivell més alt, ens focalitzem en la difusió i la seguretat de la informació. Reduïm el consum d'una mote individual en xarxes amb patrons de trànsit dinàmic mitjançant la definició d'una funció de planificació basada en el conegut controlador PID i allarguem la vida d'una WSN globalment distribuint equitativament el consum energètic de totes les motes, disminuint el nombre d'intervencions necessàries per a canviar bateries i el cost associat. Per tal d'afavorir la difusió de la informació provinent d'una WSN, hem proposat jxSensor, una capa d'integració entre les WSN i el conegut sistema P2P JXTA. Com que tractem informació sensible, hem proposat una capa d'anonimat a JXTA i un mecanisme d'autenticació lleuger per a la seva versió mòbil.Esta tesis trata las diferentes limitaciones encontradas en WSN para habilitar su despliegue en nuevos escenarios, así como facilitar la diseminación de la información obtenida. A bajo nivel, nos centramos en el consumo de energía, mientras que, a un nivel más alto, nos focalizamos en la diseminación y seguridad de la información. Reducimos el consumo de una mota individual en redes con patrones de tráfico dinámico mediante la definición de una función de planificación basada en el conocido controlador PID y alargamos la vida de una WSN globalmente distribuyendo equitativamente el consumo energético de todas las motas, disminuyendo el número de intervenciones requeridas para cambiar baterías y su coste asociado. Para favorecer la diseminación de la información procedente de una WSN hemos propuesto jxSensor, una capa de integración entre las WSN y el conocido sistema P2P JXTA. Como estamos tratando con información sensible, hemos propuesto una capa de anonimato en JXTA y un mecanismo de autenticación ligero para su versión móvil.This thesis addresses different limitations found in WSNs in order to enable their deployment in new scenarios as well as to make it easier to disseminate the gathered information. At a lower level, we concentrate on energy consumption while, at a higher level, we focus on the dissemination and security of information. The consumption of an individual mote in networks with dynamic traffic patterns is reduced by defining a scheduling function based on the well-known PID controller. Additionally, the life of a WSN is extended by equally distributing the consumption of all the motes, which reduces the number of interventions required to replace batteries as well as the associated cost. To help the dissemination of information coming from a WSN we have proposed jxSensor, which is an integration layer between WSNs and the well-known JXTA P2P system. As we are dealing with sensitive information, we have proposed an anonymity layer in JXTA and a light authentication method in its mobile version

Sistema de pesquisa automática de sequências de ADN aproximadas e não contíguas

Mestrado em Engenharia Eletrónica e TelecomunicaçõesA capacidade de efectuar pesquisas de sequências de ADN similares a outras contidas numa sequência maior, tal como um cromossoma, tem um papel muito importante no estudo de organismos e na possível ligação entre espécies diferentes. Apesar da existência de várias técnicas e algoritmos, criados com o intuito de realizar pesquisas de sequência, este problema ainda está aberto ao desenvolvimento de novas ferramentas que possibilitem melhorias em relação a ferramentas já existentes. Esta tese apresenta uma solução para pesquisa de sequências, baseada em compressão de dados, ou, mais especificamente, em modelos de contexto finito, obtendo uma medida de similaridade entre uma referência e um alvo. O método usa uma abordagem com base em modelos de contexto finito para obtenção de um modelo estatístico da sequência de referência e obtenção do número estimado de bits necessários para codificação da sequência alvo, utilizando o modelo da referência. Ao longo deste trabalho, estudámos o método descrito acima, utilizando, inicialmente, condições controladas, e, por m, fazendo um estudo de regiões de ADN do genoma humano moderno, que não se encontram em ADN ancestral (ou se encontram com elevado grau de dissimilaridade).The ability to search similar DNA sequences with relation to a larger sequence, such as a chromosome, has a really important role in the study of organisms and the possible connection between di erent species. Even though several techniques and algorithms, created with the goal of performing sequence searches, already exist, this problem is still open to the development of new tools that exhibit improvements over currently existent tools. This thesis proposes a solution for sequence search, based on data compression, or, speci cally, nite-context models, by obtaining a measure of similarity between a reference and a target. The method uses an approach based on nite-context models for the creation of a statistical model of the reference sequence and obtaining the estimated number of bits necessary for the codi cation of the target sequence, using the reference model. In this work we studied the above described method, using, initially, controlled conditions, and, nally, conducting a study on DNA regions, belonging to the modern human genome, that can not be found in ancient DNA (or can only be found with high dissimilarity rate)

The theory and implementation of a secure system

Computer viruses pose a very real threat to this technological age. As our dependence on computers increases so does the incidence of computer virus infection. Like their biological counterparts, complete eradication is virtually impossible. Thus all computer viruses which have been injected into the public domain still exist. This coupled with the fact that new viruses are being discovered every day is resulting in a massive escalation of computer virus incidence. Computer viruses covertly enter the system and systematically take control, corrupt and destroy. New viruses appear each day that circumvent current means of detection, entering the most secure of systems. Anti-Virus software writers find themselves fighting a battle they cannot win: for every hole that is plugged, another leak appears. Presented in this thesis is both method and apparatus for an Anti-Virus System which provides a solution to this serious problem. It prevents the corruption, or destruction of data, by a computer virus or other hostile program, within a computer system. The Anti-Virus System explained in this thesis will guarantee system integrity and virus containment for any given system. Unlike other anti-virus techniques, security can be guaranteed, as at no point can a virus circumvent, or corrupt the action of the Anti-Virus System presented. It requires no hardware modification of the computer or the hard disk, nor software modification of the computer's operating system. Whilst being largely transparent to the user, the System guarantees total protection against the spread of current and future viruses

Lazy transition systems and asynchronous circuit synthesis with relative timing assumptions

Journal ArticleThis paper presents a design flow for timed asynchronous circuits. It introduces lazy transitions systems as a new computational model to represent the timing information required for synthesis. The notion of laziness explicitly distinguishes between the enabling and the firing of an event in a transition system. Lazy transition systems can be effectively used to model the behavior of asynchronous circuits in which relative timing assumptions can be made on the occurrence of events. These assumptions can be derived from the information known a priori about the delay of the environment and the timing characteristics of the gates that will implement the circuit. The paper presents necessary conditions to generate circuits and a synthesis algorithm that exploits the timing assumptions for optimization. It also proposes a method for back-annotation that derives a set of sufficient timing constraints that guarantee the correctness of the circuit

Hospital Nurses\u27 Moral Distress and Coping during COVID-19: A Pilot Study

The COVID-19 pandemic caused a wave of critically ill patients, overwhelming hospitals, and creating unprecedented conditions for hospital employees, particularly bedside nurses. Concerns about the emotional and mental well-being of nurses have already been raised prior to the pandemic and depression, anxiety, and PTSD symptoms among nurses during the pandemic have been observed. Given the increased infection and safety risks, staffing shortages, inadequate personal protective equipment and resources, and hospital restrictions causing many nurses to be patients’ only support, there is also a growing concern about how these institutional and personal restrictions to providing best care and practicing ethically have impacted nurses. Moral distress is the psychological disequilibrium that occurs when a professional knows what they need to do but is/feels unable to take that action due to perceived or actual internal and/or external constraints. Much has been researched about causes of moral distress in the last 20 years, but to date, there is limited evidence around the impact of organizational support, emotional intelligence (EI), and coping strategies. This pilot study aimed to describe and explore the relationships among EI, coping, organizational support, and moral distress, and to provide pilot data and methodological information to inform a national study. Participants were Kentucky registered nurses currently working or who have worked at an inpatient hospital facility within the last six months. Participants were recruited using non-randomized purposive and snowball sampling techniques to complete an anonymous online survey using Qualtrics. Using SPSS, descriptive statistics and regression analyses examined the relationships between the independent study variables, using the Wong and Law Emotional Intelligence Scale, COVID-19 Organizational Support, Survey of Perceived Organizational Support, and the Ways of Coping Checklist Revised, and the dependent variable, moral distress, as measured by the Measurement of Moral Distress for Healthcare Professionals. Regression analysis adjusted for hospital ethical climate, intensive care setting, and age. After data cleaning and screening, there were 544 nurse participants who completed most of the demographic questionnaire items with 271 participants completing all instruments included in the regression analysis. The sample included mostly white females with Bachelor of Science in nursing working with adult populations in non-ICU settings in central Kentucky. In support of predicted relationships, organizational support was associated with a reduction in moral distress and emotion-focused coping was positively related. However, in contrast of predicted relationships, problem-focused coping was also positively related to moral distress; and while EI had a negative relationship in correlational testing, EI resulted in a non-significant positive relationship in regression analysis. Additional regression analysis showed EI maintained a negative relationship only when entered with problem-focused coping adjusted for control variables. Future research should strive for larger, more diverse samples that would allow for mediation testing to further explore the relationship between EI, coping, and moral distress. Metadata from Qualtrics will be used to inform potential changes in the structure, length and presentation of the survey for a national study

Parents\u27 Perceptions of and Experiences with School Counselors

Research has found that parents may feel isolated from their children\u27s schools due to their own problematic educational experiences or their lack of understanding their children\u27s school experiences. Current literature explores stakeholders\u27 perceptions of school counselors but lacks specific context from a parental perspective. Validating parents\u27 perceptions of and experiences with school counselors enhances students\u27 academic success by providing insight about what motivates parents to invest in their children\u27s schools and how school counselors influence parental involvement. Utilizing key concepts related to the importance of parental involvement for student success, this qualitative study focused on the experiences and perceptions of parents regarding their children\u27s high school counselors. Criterion and snowball sampling was used to recruit 8 parents from 5 different high schools across the Midwestern United States. Interview data were analyzed through clustering and horizontalization processes, revealing 4 specific themes: student benefits, in which school counselors directly supported students; parents feeling empowered, in which school counselors validated concerns and empowered parents; school counselor providing interpersonal environment, where students believed school counselors cared about them as individuals and strove for their success; and informed school counselor, where school counselors capitalized on their expertise and professional experience for the direct benefit of students. These emerging themes strengthen existing research and provide current and future school counselors with insight into building and maintaining collaborative relationships with parents, including advocacy efforts to increase student success

2009 March

Press releases for March of 2009

Identification of Transient Speech Using Wavelet Transforms

It is generally believed that abrupt stimulus changes, which in speech may be time-varying frequency edges associated with consonants, transitions between consonants and vowels and transitions within vowels are critical to the perception of speech by humans and for speech recognition by machines. Noise affects speech transitions more than it affects quasi-steady-state speech. I believe that identifying and selectively amplifying speech transitions may enhance the intelligibility of speech in noisy conditions. The purpose of this study is to evaluate the use of wavelet transforms to identify speech transitions. Using wavelet transforms may be computationally efficient and allow for real-time applications. The discrete wavelet transform (DWT), stationary wavelet transform (SWT) and wavelet packets (WP) are evaluated. Wavelet analysis is combined with variable frame rate processing to improve the identification process. Variable frame rate can identify time segments when speech feature vectors are changing rapidly and when they are relatively stationary. Energy profiles for words, which show the energy in each node of a speech signal decomposed using wavelets, are used to identify nodes that include predominately transient information and nodes that include predominately quasi-steady-state information, and these are used to synthesize transient and quasi-steady-state speech components. These speech components are estimates of the tonal and nontonal speech components, which Yoo et al identified using time-varying band-pass filters. Comparison of spectra, a listening test and mean-squared-errors between the transient components synthesized using wavelets and Yoo's nontonal components indicated that wavelet packets identified the best estimates of Yoo's components. An algorithm that incorporates variable frame rate analysis into wavelet packet analysis is proposed. The development of this algorithm involves the processes of choosing a wavelet function and a decomposition level to be used. The algorithm itself has 4 steps: wavelet packet decomposition; classification of terminal nodes; incorporation of variable frame rate processing; synthesis of speech components. Combining wavelet analysis with variable frame rate analysis provides the best estimates of Yoo's speech components