Indoor positioning is a rapidly growing research area, enabling new innovative location-aware applications and user-oriented services. Location Fingerprinting (LF) is the positioning technique of coupling a physical location with observed radio signal measurements. In the terms of indoor LF using Wireless Local Area Network (WLAN) it refers to the use of network measurements from the WLAN Access Points (APs) to tag known locations. A data set is created containing reference fingerprints for the area of interest and is known as a radio map. A radio map can later be used to find a user's location in the area of interest. WLAN infrastructures are vulnerable to many kinds of faults and malicious attacks, including, an attacker jamming the signal from an AP, or an AP becoming unavailable during positioning due to power outage. These faults can be collectively characterized as an AP-failure. In LF positioning systems, AP-failure faults can significantly degrade the performance of a LF system due to the difference between the current fingerprints and radio map created with all APs being available. It is desirable to detect such faulty APs, in order to take actions towards fault-mitigation and restoration, in case of a malicious attack. In this work, we have developed a fault detection algorithm that uses inertial sensors (i.e., accelerometer, magnetometer) available in smartphones to detect AP-failure faults in LF systems. Inertial Measurement Unit (IMU) has become an integral part of all high-end smartphones. IMU can be used to infer location information on the smartphone. The main idea is to have two parallel position streams, the LF positioning and the IMU positioning, and to compare the mean positioning error between the two. Since IMU positioning is fairly accurate once provided with starting coordinates, we use it to detect abnormal behaviour in LF positioning system, such as highly erroneous estimates signifying an AP-failure fault present in the system. The performance of the proposed detection algorithm is evaluated with several real-life AP-related faults. The proposed algorithm exhibits low probability of false alarms in the detection of faulty APs. The conclusion is that using IMU based positioning is an effective and robust solution in terms of fault detection in LF systems.

A pertinent educational issue in our country today is the minority achievement gap. One specific program that has been developed and implemented over the last several years in an effort to provide strong academic curriculum and to raise student achievement, including minority student achievement, is the College Board's Advanced Placement (AP) Program. The AP Program courses are widely recognized as providing students with academically challenging curriculum, facilitating their acceptance to colleges and supporting their preparation for and performance in post-secondary education. The emphasis of this research relates to the specific concern that although the AP Program has been in existence for several decades and is an integral part of most high schools' curriculum for at least ten years, there is an under-representation of minority students in high school Advanced Placement (AP) Program courses. This qualitative research involved completing an in-depth case study of a designated secondary school in the Mid-Atlantic region that has been successful in recruiting and enrolling students, majority and minority, in the AP Program. Guiding questions for this case study related to identifying the individuals who influenced enrollment, as well as the policies, procedures, interventions, and strategies used to recruit students and increase their enrollment in AP courses. These research findings revealed various key factors that contributed to the success of increasing student enrollment in these academic courses and the factors are similar to those identified in the literature and other research studies. These factors include: (a) shared and distributed leadership demonstrated across the school; (b) collaborative vision and mission; (c) an AP Program with high expectations and a relevant and rigorous curriculum; (d) strong academic advisement, data-driven decision making, and specific school policies and procedures related to the AP Program; (e) extended student learning opportunities and individualized support; and (f) varied professional development and training for faculty. This case study highlights a group of dedicated and committed leaders with collaborative vision who implemented an academic program with focused initiatives and interventions. Between 2003 and 2009, this school increased overall student enrollment in the AP Program by 15.2%, with the Black student enrollment increasing by 11.9% and the Hispanic student enrollment increasing by 10.5%. They accomplished their goal and commitment to increasing minority enrollment in the AP Program and providing enriched academic learning opportunities for all students. / Ed. D.

Phishing is an internet security issue whose shape is still changing and size is still increasing. This thesis shows the possibility of a phishing attack on open, private Wireless LANs. Private WLANs which use a login page to authenticate users in hotels, airports and academic campuses are all vulnerable to this attack. Virginia Tech's WLAN is used as an example to show that the attack is possible. The attack combines two very well known attacks: one is to deceptively guide a user into logging into a fake website, which shows similar log-in page to the page of the website the user intends to go to, and the second attack is to show users a valid certificate, which does not show a warning. The rogue server takes the user to a log-in page which is similar to Virginia Tech's log-in page and shows him a valid security certificate. We present a solution to the proposed problem. Software is implemented that runs on Windows Vista. The software warns the user if there are servers with more than one type of security certificates, claiming to be from the same network. We contrast our method to already existing methods, and show in what respects our solution is better. The biggest advantage of this method is that it involves no change on the server side. It is not necessary for the users to have any prior knowledge of the network, which is very helpful when the users access WLAN at airports and hotels. Also, when using this method, the user does not need to connect to any network, and is still able to get a warning. It however, requires the user to be able to differentiate between the real and fake networks after the user has been warned. / Master of Science

No description available.

SILVA, Alzira Nogueira da. Pegando vida nas mãos: um olhar etnográfico sobre saberes e práticas das parteiras tradicionais nos circuitos do Amapá em mudanças. 2005. 189f. – Dissertação (Mestrado) – Universidade Federal do Ceará, Programa de Pós-graduação em Sociologia, Fortaleza (CE), 2005. / Submitted by Márcia Araújo (marcia_m_bezerra@yahoo.com.br) on 2014-03-21T11:31:27Z No. of bitstreams: 1 2005-DIS-ANSILVA.pdf: 3895946 bytes, checksum: 0d9df929e4fc05616c24c0277329f298 (MD5) / Approved for entry into archive by Márcia Araújo(marcia_m_bezerra@yahoo.com.br) on 2014-03-21T11:38:12Z (GMT) No. of bitstreams: 1 2005-DIS-ANSILVA.pdf: 3895946 bytes, checksum: 0d9df929e4fc05616c24c0277329f298 (MD5) / Made available in DSpace on 2014-03-21T11:38:12Z (GMT). No. of bitstreams: 1 2005-DIS-ANSILVA.pdf: 3895946 bytes, checksum: 0d9df929e4fc05616c24c0277329f298 (MD5) Previous issue date: 2005 / Hand Delivering: An Ethnographic Outlook on Changing Knowledge and Practices of Traditional Midwives (“Pegando Vida nas Mãos”: um olhar etnográfico sobre saberes e práticas das parteiras tradicionais nos circuitos do Amapá em mudanças) is the upshot of an investigative trail followed in the pursuit of unveiling the world of knowledge and practices of traditional midwives from Mazagao/Amapa. The investigation is set within the realm of the Social Sciences shaping up an ethnographic study that encompasses a frontier area between Sociology and Anthropology. Indeed, I tried to develop a sociological approach about a web of relations that define the profession of traditional midwives resorting to a methodological tool from ethnography. To set out on this ethnographic adventure I took as a basic assumption the thesis that the job of helping delivery implies an interaction process of “midwife and parturient” that includes partnership, female solidarity, power struggle, respect and leadership that add to this relation a complex web of feelings for the sharing of life and culture. My analysis posts knowledge and practices, as seen by the performance of traditional midwives from Mazagao, within peculiar sociability forms in traditional communities in the Amazon basin in order to grasp the meaning of multiple converging elements produced by knowledge and practices of women from the region. In this investigation I tried to unveil the web of meanings that involves the traditional practice of midwives from Mazagao within conflicting dynamics of meanings found in their knowledge/practices considering that within a given political context those practices and the web that they form go through changes and adjustments according to intervention programs of the State that sometimes have punctual and temporary aspects that impact the informal webs. / Pegando Vida nas Mãos: um olhar etnográfico sobre saberes e práticas das parteiras tradicionais nos circuitos do Amapá em mudanças é fruto do percurso de investigação, trilhado no sentido de descortinar um universo de significados dos saberes e das práticas das parteiras tradicionais de Mazagão/Amapá. Esta investigação situa-se no âmbito das ciências sociais, configurando um estudo etnográfico, numa área de fronteira entre a Sociologia e a Antropologia. De fato, busquei construir um olhar sociológico sobre a teia de relações que circunscrevem o ofício das parteiras tradicionais, valendo-me do instrumental metodológico da etnografia. Nesta aventura etnográfica, tomei como pressuposto fundante, a tese de que o trabalho de partejar implica um processo de interações “parteira-parturiente” que envolve cumplicidade, solidariedade feminina, disputa de poder, respeito e liderança, conferindo a esta relação uma complexidade de sentidos na da partilha de vida e de cultura. Minha análise situa os saberes e práticas das parteiras tradicionais de Mazagão no interior das formas peculiares de sociabilidade nas comunidades tradicionais amazônicas, apreendendo as múltiplas convergências gestadas nos saberes e fazeres das mulheres desta região. Nesta investigação, busquei desvendar as redes de significados que envolvem a prática tradicional das parteiras de Mazagão no contexto da dinâmica contraditória de (re)significações de seus saberes/fazeres, compreendendo que em contextos políticos específicos, essas práticas e as redes que as articulam experimentam mudanças e adequações em função de programas de intervenção do Estado que, algumas vezes, têm caráter pontual e temporário, causando impacto nas redes informais.

Orientador: Celia Maria Marinho de Azevedo / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciencias Humanas / Made available in DSpace on 2018-07-28T21:58:14Z (GMT). No. of bitstreams: 1 Goncalves_MarianadeAraujo_M.pdf: 7838853 bytes, checksum: f6cf659296938ac4cfdd38571a9aa71e (MD5) Previous issue date: 2001 / Resumo: Este trabalho analisa história e identidade no carnaval das escolas de samba em Macapá. Através de letras de sambas-enredos e entrevistas com "fazedores de carnaval" desenvolve-se uma reflexão sobre formas e sentidos que grupos negros locais elaboraram para legitimarem-se no lugar e nas lutas por ascensão social. A construção de uma memória discursiva e de uma identidade cultural são as marcas de uma utilização do passado / Abstract: This work analyzes history and identity in the carnival of the samba schools in Macapá, Amapá. Using drafts of samba-lots and enterviews with "carnival makers", it aims to reflect on the modes and meanings that local blacks groups elaborate for achieving a better social position. The construction of a discursive memory and a cultural identity are the token of the uses of the post / Mestrado / Mestre em História

No description available.

O objetivo deste estudo foi investigar longitudinalmente a transmissão de Streptococcus mutans em um grupo de famílias brasileiras de baixa renda. Um critério de inclusão importante foi o de todos os adultos conviverem na mesma casa com a criança. Participaram da pesquisa 14 mães, pais e crianças e 8 avós. Amostras de saliva das crianças foram coletadas em quatro visitas durante 22 meses, para pesquisa de S.mutans. Foram positivas apenas 8 crianças, que tiveram os seus isolados e os isolados de suas famílias identificados pelo método de hibridização DNA-DNA. Um total de 506 isolados de S.mutans foi genotipado pelo método de AP-PCR, usando o primer OPA-02. Foram detectados 20 genótipos diferentes nas 8 famílias, variando de 1 a 5 nos adultos e 1-2 nas crianças. Todas as mães e alguns pais e avós compartilharam genótipos com as crianças. Em todas as famílias foram encontrados genótipos homólogos nos adultos. Alguns genótipos foram estáveis, e outros, se perderam, mas o compartilhamento pode favorecer a contínua reinfecção. Três crianças desenvolveram cárie no período. O encontro de genótipos de cada membro da família na criança e o compartilhar de genótipos nos adultos, sugerem uma reavaliação de modelos preventivos antimicrobianos focalizados apenas na figura materna. / The objective of this study was to investigate in a longitudinal study the transmission of Streptococcus mutans in Brazilian families of a low socioeconomic status. An important entry criterion for the study was to include all members of a household in the study. The study cohort was comprised of 14 mothers, fathers and children and 8 grandmothers. Saliva samples were collected for S. mutans analysis in 4 visits during 22 months. Only eight children were positive for S. mutans by employing DNA-DNA hybridization that was also applied to household members. A total of 506 isolates of S. mutans were genotyped by AP-PCR with the primer OPA-02. Twenty genotypes were detected in 8 families ranging from 1 to 5 in the adults and 1-2 in the children. All mothers and some fathers and grandmothers shared similar genotypes with the children. In all families homologous genotypes were encountered among adults. Some genotypes were stable, and others were lost although sharing a similar environment may favor additional transmission episodes. Three children developed decay during the study period. The fact that children shared genotypes from all household members suggest that reevaluation of preventive methods aimed at suppressing S. mutans infections should include additional family members and not only the mothers.

Energetic materials are a class of material that have large amounts of chemical energy stored within their molecular structure. This energy is released upon decomposition, generally in the form of rapidly expanding, hot gases. They are therefore used for a wide range of applications such as; mining, military, and space exploration, and there is therefore a strong desire to improve the overall performance and safety of such materials. On account of reduced sensitivity to initiation by shock and impact, 2,4-dinitroanisole (DNAN) is a potential replacement for 2,4,6-trinitrotoluene (TNT) in melt-cast formulations for military applications. However, up to 15 % irreversible growth of DNAN has been previously observed upon thermal cycling and is a key reason why DNAN has not yet been universally accepted as a replacement for TNT. DNAN exhibits a complex system of polymorphism. One particular transition from DNAN-II to DNAN-III, which occurs at 266 K, has been observed in these studies to cause 8 - 10 % growth of DNAN-II pellets when temperature cycled for 30 cycles between 256 K and 276 K. What was even more concerning was the appearance of cracking of DNAN pellets after being temperature cycled. Doping the crystal structure of DNAN-II with related molecules, such as 2,4-dinitrotoluene or 2,4-dinitroaniline, was investigated in order to probe how steric and electronic factors affect the transition. The addition of varying amounts of 2,4-dinitroaniline suppressed this transition to varying extents and ultimately as low as 150 K with 10 mol% 2,4-dinitroaniline, and potentially eliminated entirely. This doped material has been designated as phase-stabilised DNAN (PS-DNAN). Temperature cycling of PS-DNAN was conducted over the same 256-276 K range, and this material showed no evidence of irreversible growth compared to undoped DNAN pellets, on account of suppression of the II-III transition. The production of PS-DNAN is therefore a possible route to avoiding problematic irreversible growth in DNAN formulations. Melt-casting of DNAN in a sealed environment consistently results in the metastable form-II, which has proven to be stable for in excess of 32 weeks. However, exposure to seeds of form-I, either via deliberate or accidental seeding, rapidly converted the material to the thermodynamically more stable form-I. This transition was accelerated by increasing temperature which rapidly converted pellets of DNAN-II to DNAN-I. When DNAN-I pellets were temperature cycled, they did not undergo a transition to form-III, and as a result did not illustrate irreversible growth. This presents another approach to avoiding problematic growth in DNAN-based materials. Whilst being one of the most widely used oxidisers in propellant formulations, ammonium perchlorate (AP) has several issues; the formation of porous ammonium perchlorate (PAP) can seriously affect the sensitivity of propellants, the hygroscopicity of AP makes handling and manufacture of formulations difficult, and spherical AP exhibits poor binding properties to the polymer binders used in propellant formulations. Several different approaches were taken to combat these issues. Co-crystallisation of AP was attempted in order to produce new AP co-crystals with reduced reactivity towards the formation of PAP. A theoretical based approach using COSMOtherm was used for rapid screening and selection of potential co-formers to be used in lab-based co-crystallisation trials. Co-crystallisation was attempted using multiple stoichiometries and multiple solvents by solvent evaporation, cooling crystallisation, and Resonant Acoustic Mixing methods. Unfortunately no new co-crystals were obtained, presumably on account of the ionic nature of AP which makes co-crystallisation difficult. The mass of untreated AP increased by 0.027% in a humid environment (90% RH) due to the uptake of water, which resulted in significant caking and hence hindering the processability of AP. In an attempt to counteract the hygroscopicity and improve the processability of AP, particles of AP were coated in graphene nanoplatelets using the technique of Resonant Acoustic Mixing. Low mixing energy (G-force) (30 G) resulted in poor coating of AP, but the flowability of this mixure after exposure to moisture was significantly enhanced, most probably as a result of graphene acting as an effective lubricant. Higher mixing energy (90-100 G) was required to break up agglomerates of graphene nanoplatelets and resulted in AP particles efficiently coated with graphene (APGR). Differential scanning calorimetry showed that the energy released upon decomposition of APGR was greater than pure AP, or AP mixed with graphene, due to the intimacy of the AP particle surface and the graphene coating.

Composite propellants are composed of a solid oxidizer that is mixed into a hydrocarbon binder that when polymerized results in a solid mass capable of selfsustained combustion after ignition. Plateau propellants exhibit burning rate curves that do not follow the typical linear relationship between burning rate and pressure when plotted on a log-log scale, and because of this deviation their burning behavior is classified as anomalous burning. It is not unusual for solid-particle additives to be added to propellants in order to enhance burning rate or other properties. However, the effect of nano-size solid additives in these propellants is not fully understood or agreed upon within the research community. The current project set out to explore what possible variables were creating this result and to explore new additives. This thesis contains a literature review chronicling the last half-century of research to better understand the mechanisms that govern anomalous burning and to shed light on current research into plateau and related propellants. In addition to the review, a series of experiments investigating the use of nanoscale TiO2-based additives in AP-HTPB composite propellants was performed. The baseline propellant consisted of either 70% or 80% monomodal AP (223 μm) and 30% or 20% binder composed of IPDI-cured HTPB with Tepanol. Propellants’ burning rates were tested using a strand bomb between 500 and 2500 psi (34.0-170.1 atm). Analysis of the burning rate data shows that the crystal phase and synthesis method of the TiO2 additive are influential to plateau tailoring and to the apparent effectiveness of the additive in altering the burning rate of the composite propellant. Some of the discrepancy in the literature regarding the effectiveness of TiO2 as a tailoring additive may be due to differences in how the additive was produced. Doping the TiO2 with small amounts of metallic elements (Al, Fe, or Gd) showed additional effects on the burning rate that depend on the doping material and the amount of the dopant.