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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Investigate options with spectrum scanning applications

Bergström, Edwin January 2024 (has links)
This thesis investigates the possibilities of Software-defined radios as a surveillance system by monitoring the electromagnetic spectrum. The surveillance system monitors the Bluetooth bandwidth with a multi-channel receiver that passively listens to Bluetooth packets. Furthermore, this thesis investigates the possibility of implementing an automatic k-means clustering algorithm to count unique devices in the vicinity. The Background explains the fundamental technologies used in Bluetooth and explains how devices communicate with each other. The Background also explains the proposed receiver architecture and its technologies. Section Related work and similar products investigate different approaches to detecting mobile devices and the effectiveness of the k-means algorithm. The Method explains how the receiver is modeled, how the Python script identifies Bluetooth packets in the bit stream, and how the physical imperfections are collected for the automatic k-means algorithm. Lastly, the Method explains how the labs were conducted. The Result section shows the performance of the receiver and the k-means algorithm. The Discussion section analyzes the results and discusses some design flaws and how to fix them potentially. Lastly, the Conclusion section compares the goals with the results and presents future work for further development.
12

Implicações da remoção de fezes de por Scarabaeinae (Coleoptera: Scarabaeidae) sobre a avaliação de aspectos ecológicos de Mazama (Artiodactyla: Cervidae), na Amazônia / Implications of feces removal by Scarabaeinae (Coleoptera: Scarabaeidae) on evaluation of ecological aspects of Mazama (Artiodactyla: Cervidae) in the Amazon

Cerveira, Josi Fernanda 01 September 2016 (has links)
Duas espécies de cervídeos florestais ocorrem em simpatria na Amazônia: Mazama americana e Mazama nemorivaga. Ambas apresentam hábitos solitários e comportamento elusivo e por isso são difíceis de serem capturados. Além disso, são extremamente sensíveis aos métodos de captura os quais quase sempre implicam em altos níveis de estresse e injúrias. A utilização de DNA fecal tem sido empregada como alternativa não invasiva à captura, uma vez que, a partir do DNA extraído das fezes, é possível a identificação da espécie, sexo e identificação dos indivíduos. Cães farejadores vem sendo utilizados para aumentar a detecção das amostras fecais em campo e tem sido importantes aliados em estudos populacionais de cervídeos no Cerrado, Pantanal e Mata Atlântica. Nestes biomas a permanência das fezes pode ser favorecida por questões climáticas e/ou por características locais da biota especializada na degradação e remoção de excrementos. Trabalhos que utilizam fezes como fonte de informação na Amazônia não estão disponíveis bem como também não são suficientemente conhecidos os parâmetros inerentes a degradação e remoção de fezes naquele bioma. Neste sentido, este trabalho foi desenvolvido em uma área protegida do sudeste da Amazônia (Floresta Nacional do Jamari, Rondônia) e faz uma síntese sobre as implicações ecológicas da remoção de fezes de cervídeos de Mazama por coleópteros Scarabaeinae. Discute-se aqui: 1. A composição, riqueza e abundância de escarabaeíneos onde verificou-se a predileção por fezes frescas independente da espécie de cervídeo; 2. A elevada taxa de remoção das fezes na região amazônica onde verificamos taxas: (i) máxima: 100 pellets removidos em uma hora (4,5% das amostras) e; (ii) mínima: 100 pellets removidos entre 12 a 24 horas (58% das amostras) e; 3. A diversidade de ácaros foréticos Macrochelidae coletados durante a triagem dos Scarabaeinae. Por fim, apresento um modelo conceitual sobre a inobservância de amostras fecais para Amazônia onde considero dados empíricos de remoção por coleópteros aliados à experiência de busca ativa de fezes com cão farejador e com dados de presença e abundância de cervídeos obtidas com armadilhas fotográficas. Os treinamentos mostraram que o cão fora eficiente em encontrar fezes e o armadilhamento mostraram boa frequência das espécies de Mazama, contudo, a efetiva ação dos escarabeídeos mostrou-se um importante obstáculo as intenções de se obter amostras moleculares através de fezes na Amazônia. / Two species of forest deer occur sympatric in the Amazon: Mazama americana and Mazama nemorivaga. Both have solitary habits and elusive behavior and so are difficult to capture. Moreover, they are extremely sensitive to catching methods which often involve high levels of stress and injuries. The use of fecal DNA has been employed as a noninvasive alternative to capturing, since is possible made species identification, identification of individuals and sexing by DNA extracted from stools. Sniffer dogs have been used to increase the detection of fecal samples in the field and it has been important allies in population studies of deer in the Cerrado, Pantanal and Atlantic Forest. In these biomes the persistence of feces can be favored by climatic reasons and / or by local characteristics of specialized biota in the degradation and removal of excreta. Studies that use feces as a source of information in the Amazon are not available and also are not sufficiently known the parameters inherent of degradation and removal of feces in that biome. Thus, this study was conducted in a protected area of southeastern Amazon (Jamari National Forest, Rondonia) and provides an overview of the ecological implications of the removal of deer stool\'s Mazama by dung beetles Scarabaeinae. It is discussed here: 1. The composition, richness and abundance of Scarabaeinae where there was a predilection for fresh feces independently of the deer species; 2. The high rate of stool removal in the Amazon where we see: (i) maximum rate: 100 pellets removed in an hour (4.5% of the samples) and; (Ii) minimum rate: 100 pellets removed between 12 and 24 hours (58% of samples) and; 3. The diversity of Macrochelidae phoretic mites collected during the screening of Scarabaeinae. Finally, I present a conceptual model about detection failure of fecal samples to Amazon where I consider removal data by Coleoptera combined the experience of active search of stool with sniffer dog and data of presence and abundance of deer taken with camera traps. The training showed that the dog was efficient in finding feces and trapping showed good frequency of Mazama species, however, the effective action of scarabs proved to be a major obstacle to the intentions to obtain molecular samples through feces in the Amazon.
13

Implicações da remoção de fezes de por Scarabaeinae (Coleoptera: Scarabaeidae) sobre a avaliação de aspectos ecológicos de Mazama (Artiodactyla: Cervidae), na Amazônia / Implications of feces removal by Scarabaeinae (Coleoptera: Scarabaeidae) on evaluation of ecological aspects of Mazama (Artiodactyla: Cervidae) in the Amazon

Josi Fernanda Cerveira 01 September 2016 (has links)
Duas espécies de cervídeos florestais ocorrem em simpatria na Amazônia: Mazama americana e Mazama nemorivaga. Ambas apresentam hábitos solitários e comportamento elusivo e por isso são difíceis de serem capturados. Além disso, são extremamente sensíveis aos métodos de captura os quais quase sempre implicam em altos níveis de estresse e injúrias. A utilização de DNA fecal tem sido empregada como alternativa não invasiva à captura, uma vez que, a partir do DNA extraído das fezes, é possível a identificação da espécie, sexo e identificação dos indivíduos. Cães farejadores vem sendo utilizados para aumentar a detecção das amostras fecais em campo e tem sido importantes aliados em estudos populacionais de cervídeos no Cerrado, Pantanal e Mata Atlântica. Nestes biomas a permanência das fezes pode ser favorecida por questões climáticas e/ou por características locais da biota especializada na degradação e remoção de excrementos. Trabalhos que utilizam fezes como fonte de informação na Amazônia não estão disponíveis bem como também não são suficientemente conhecidos os parâmetros inerentes a degradação e remoção de fezes naquele bioma. Neste sentido, este trabalho foi desenvolvido em uma área protegida do sudeste da Amazônia (Floresta Nacional do Jamari, Rondônia) e faz uma síntese sobre as implicações ecológicas da remoção de fezes de cervídeos de Mazama por coleópteros Scarabaeinae. Discute-se aqui: 1. A composição, riqueza e abundância de escarabaeíneos onde verificou-se a predileção por fezes frescas independente da espécie de cervídeo; 2. A elevada taxa de remoção das fezes na região amazônica onde verificamos taxas: (i) máxima: 100 pellets removidos em uma hora (4,5% das amostras) e; (ii) mínima: 100 pellets removidos entre 12 a 24 horas (58% das amostras) e; 3. A diversidade de ácaros foréticos Macrochelidae coletados durante a triagem dos Scarabaeinae. Por fim, apresento um modelo conceitual sobre a inobservância de amostras fecais para Amazônia onde considero dados empíricos de remoção por coleópteros aliados à experiência de busca ativa de fezes com cão farejador e com dados de presença e abundância de cervídeos obtidas com armadilhas fotográficas. Os treinamentos mostraram que o cão fora eficiente em encontrar fezes e o armadilhamento mostraram boa frequência das espécies de Mazama, contudo, a efetiva ação dos escarabeídeos mostrou-se um importante obstáculo as intenções de se obter amostras moleculares através de fezes na Amazônia. / Two species of forest deer occur sympatric in the Amazon: Mazama americana and Mazama nemorivaga. Both have solitary habits and elusive behavior and so are difficult to capture. Moreover, they are extremely sensitive to catching methods which often involve high levels of stress and injuries. The use of fecal DNA has been employed as a noninvasive alternative to capturing, since is possible made species identification, identification of individuals and sexing by DNA extracted from stools. Sniffer dogs have been used to increase the detection of fecal samples in the field and it has been important allies in population studies of deer in the Cerrado, Pantanal and Atlantic Forest. In these biomes the persistence of feces can be favored by climatic reasons and / or by local characteristics of specialized biota in the degradation and removal of excreta. Studies that use feces as a source of information in the Amazon are not available and also are not sufficiently known the parameters inherent of degradation and removal of feces in that biome. Thus, this study was conducted in a protected area of southeastern Amazon (Jamari National Forest, Rondonia) and provides an overview of the ecological implications of the removal of deer stool\'s Mazama by dung beetles Scarabaeinae. It is discussed here: 1. The composition, richness and abundance of Scarabaeinae where there was a predilection for fresh feces independently of the deer species; 2. The high rate of stool removal in the Amazon where we see: (i) maximum rate: 100 pellets removed in an hour (4.5% of the samples) and; (Ii) minimum rate: 100 pellets removed between 12 and 24 hours (58% of samples) and; 3. The diversity of Macrochelidae phoretic mites collected during the screening of Scarabaeinae. Finally, I present a conceptual model about detection failure of fecal samples to Amazon where I consider removal data by Coleoptera combined the experience of active search of stool with sniffer dog and data of presence and abundance of deer taken with camera traps. The training showed that the dog was efficient in finding feces and trapping showed good frequency of Mazama species, however, the effective action of scarabs proved to be a major obstacle to the intentions to obtain molecular samples through feces in the Amazon.
14

The nesting ecology of bumblebees

O'Connor, Stephanie A. January 2013 (has links)
Bumblebees have undergone dramatic declines both in Britain and further afield during the last century. Bumblebees provide a crucial pollination service to both crops and wild flowers. For these reasons, they have received a great deal of research attention over the years. However, the ecology of wild bumblebee nests and the interactions between nests and other species, particularly vertebrates has been somewhat understudied. This is largely due to the difficulty in finding sufficient nests for well replicated study and a lack of appropriate methods of observation. Here, methods for locating bumblebee nests were trialled. It was found that a specially trained bumblebee nest detection dog did not discover nests any faster than people who had received minimal instruction. Numbers of nest site searching queens provide a reliable indication of suitable nesting habitat (i.e. places where nests are more likely to be found). In order to investigate aspects of bumblebee nesting ecology wild nests were observed by filming or regular observations by either researchers or members of the public. Some buff-tailed bumblebee (Bombus terrestris) nests were collected and all the bumblebees were genotyped to identify any foreign individuals. A review of British mammalian dietary literature was conducted to identify those that predate bumblebees. Great tits (Parus major) were filmed predating bumblebees at nests and it was clear from the literature and observations that badger (Meles meles), pine martens (Martes martes) and hedgehogs (Erinaceus europaeus) predate bumblebee nests, as well as the wax moth (Aphomia sociella). No evidence for predation by any other vertebrate species was found. Behaviours recorded included parasitism by Psithyrus, apparent nectar theft and possible usurpation by true bumblebees, egg-dumping by foreign queens and drifting and drifter reproduction by foreign workers. These events may cause harm to colonies (for example, through horizontal transmission of pathogens, or exploitation of the host nest’s resources). Alternatively where for example, usurpation by true bumblebees, egg-dumping or drifting is successful, these alternative reproductive strategies may increase the effective population size by enabling a single nest to produce reproductives of more than one breeding female. These data found that wild buff-tailed bumblebees (B. terrestris) nests with a greater proportion of workers infected with Crithidia bombi were less likely to produce gynes than those with fewer infected workers. Gyne production also varied dramatically between years. There is a growing body of evidence that a class of frequently used insecticides called neonicotinoids are negatively impacting bumblebees. An experiment was conducted using commercial colonies of buff-tailed bumblebees (B. terrestris) which were fed pollen and nectar which had been treated with the neonicotinoid imidacloprid at field realistic, sub-lethal levels. Treated colonies, produced 85-90% fewer gynes than control colonies. If this trend is representative of natural nests feeding on treated crops, for example, oilseed rape and field beans or garden flowers, then this would be expected to cause dramatic population declines. In this thesis methods for locating bumblebee nests have been tested, new behaviours have been identified (for example, egg-dumping by queens and predation by great tits) and estimations for rates of fecundity and destruction by various factors have been provided. Doubt has been cast over the status of some mammals as predators of bumblebee nests and estimates for gyne production, nest longevity, etc, have been given. More work is needed, especially observations of incipient nests as this is when the greatest losses are thought to occur.
15

Aspekte van deursoeking en beslaglegging in Suid Afrikaanse openbare skole : n Vergelykende studie

Van Rensburg, Angelique Gene Janse 06 1900 (has links)
Afrikaans text / The Canadian and South African legal systems established equivalent constitutional values and principles pertaining to searches conducted with or without a valid search warrant. It creates the basis for a comparative study on this particular aspect. The Supreme Court of Canada held in R v A. M 2008 S.C.C 19 random sniffer dog searches conducted without neither a reasonable suspicion nor any legislative authority on learners enrolled in public schools, is unconstitutional due to its infringement of a learner's reasonable expectation to privacy, as protected in section 8 of the Canadian Charter of rights and Freedoms. South African learners are randomly search by law enforcement officers by using sniffer dogs for purposes of detecting the possession of illegal drugs in instances without neither a reasonable suspicion nor statutory authority. The search is subsequently conducted in terms of the common law. The common law is not regarded as law of general application to limit a fundamental right in terms of the limitation clause. By taking into consideration the ratio in R v A. M (supra) the conclusion is subsequently that random sniffer dog searches conducted on learners in South African public schools, without neither a reasonable suspicion nor statutory authority, is unconstitutional which infringes section 14 of the Constitution of South Africa of 1996. / Die basis vir hierdie studie is ontleen aan die ooreenstemmende vereistes en beginsels in die Kanadese en Suid Afrikaanse reg ten aansien van deursoekings met of sonder 'n wettige lasbrief uitgevoer. In die Kanadese beslissing van R v A.M 2008 SCC 19 is die grondwetlikheid van ewekansige deursoekings met behuip van snuffelhonde op leerders sonder statutere magtiging uitgevoer, deur die Supreme Court of Canada as ongrondwetlik bevind aangesien 'n leerder wel oor 'n redelike verwagting op privaatheid beskik. Indien leerders sonder 'n redelike vermoede en statutere magtiging met behuip van snuffelhonde deursoek word, geskied dit ingevolge die gemenereg en dit word nie beskou as 'n algemeen geldende reg om 'n fundamentele reg kragtens die beperkingsklousule te beperk nie. Met inagneming van die ratio in R v A.M (supra) kan daar dus tot die gevolgtrekking gekom word dat ewekansige deursoekings met behulp van snuffelhonde op Suid Afrikanse leerders in die afwesigheid van 'n redelike vermoede asook sonder statutere magtiging uitgevoer, tans ongrondwetlike optrede daarstel wat op artikel 14 van die Grondwet van 1996 inbreuk maak. / Law (College) / LL.M.
16

Aspekte van deursoeking en beslaglegging in Suid Afrikaanse openbare skole : n Vergelykende studie

Van Rensburg, Angelique Gene Janse 06 1900 (has links)
Afrikaans text / The Canadian and South African legal systems established equivalent constitutional values and principles pertaining to searches conducted with or without a valid search warrant. It creates the basis for a comparative study on this particular aspect. The Supreme Court of Canada held in R v A. M 2008 S.C.C 19 random sniffer dog searches conducted without neither a reasonable suspicion nor any legislative authority on learners enrolled in public schools, is unconstitutional due to its infringement of a learner's reasonable expectation to privacy, as protected in section 8 of the Canadian Charter of rights and Freedoms. South African learners are randomly search by law enforcement officers by using sniffer dogs for purposes of detecting the possession of illegal drugs in instances without neither a reasonable suspicion nor statutory authority. The search is subsequently conducted in terms of the common law. The common law is not regarded as law of general application to limit a fundamental right in terms of the limitation clause. By taking into consideration the ratio in R v A. M (supra) the conclusion is subsequently that random sniffer dog searches conducted on learners in South African public schools, without neither a reasonable suspicion nor statutory authority, is unconstitutional which infringes section 14 of the Constitution of South Africa of 1996. / Die basis vir hierdie studie is ontleen aan die ooreenstemmende vereistes en beginsels in die Kanadese en Suid Afrikaanse reg ten aansien van deursoekings met of sonder 'n wettige lasbrief uitgevoer. In die Kanadese beslissing van R v A.M 2008 SCC 19 is die grondwetlikheid van ewekansige deursoekings met behuip van snuffelhonde op leerders sonder statutere magtiging uitgevoer, deur die Supreme Court of Canada as ongrondwetlik bevind aangesien 'n leerder wel oor 'n redelike verwagting op privaatheid beskik. Indien leerders sonder 'n redelike vermoede en statutere magtiging met behuip van snuffelhonde deursoek word, geskied dit ingevolge die gemenereg en dit word nie beskou as 'n algemeen geldende reg om 'n fundamentele reg kragtens die beperkingsklousule te beperk nie. Met inagneming van die ratio in R v A.M (supra) kan daar dus tot die gevolgtrekking gekom word dat ewekansige deursoekings met behulp van snuffelhonde op Suid Afrikanse leerders in die afwesigheid van 'n redelike vermoede asook sonder statutere magtiging uitgevoer, tans ongrondwetlike optrede daarstel wat op artikel 14 van die Grondwet van 1996 inbreuk maak. / Law (College) / LL.M.
17

Evaluation of industrial wireless communications systems’ security

Soderi, S. (Simone) 07 June 2016 (has links)
Abstract The worldwide success of wireless communications was originally fueled by the possibility to replace existing cables with wireless solutions. This phenomenon imposed the development of security engineering as a multidisciplinary field. Although wireless solutions can reduce installation costs and allow introducing new services, the end–users expect it to have the same level of security as they would normally have with wired solutions. Secure communications is an important part of the overall security of industrial wireless communications systems (IWCS). The aim of this thesis is to develop new security engineering methodologies for IWCS. The author develops countermeasures against confidentiality and integrity attacks and carries out a security analysis covering the protocol, electromagnetic and physical layer. In the first part of the thesis, Host Identity Protocol (HIP) is utilized to secure communication in an intra–vehicular network. Simulations and measurement campaigns are also conducted to evaluate the impact of the overhead on security in a tunnel, considering line–of–sight (LOS) and non–LOS (NLOS) scenarios. Electromagnetic analysis (EMA) is an important step in the development of safety–related systems. Today, the increasing usage of smaller integrated circuit also increases the susceptibility to electromagnetic (EM) interference. From near–field (NF) to far–field (FF) transformation, a method for the evaluation of the emissions leakage is investigated. The virtual EM (VEM) interface of the device–under–test (DUT) is studied, and it is described how an adversary can exploit it for denial of service (DoS) attacks. An effective jamming attack model is studied, and the theoretical calculations are validated with experiment–based results. Finally, focusing attention on physical layer security, two algorithms are developed. Active radio frequency fingerprinting (RFF) implements the exchange of a public key during the setup of secure communication. Afterwards, utilizing a jamming receiver in conjunction with the spread spectrum (SS) watermarking technique, the watermark–based blind physical layer security (WBPLSec) protocol is presented. The analysis and results indicate how the WBPLSec seems to be a valuable technique for deploying physical layer security by creating a secure region around the receiver. / Tiivistelmä Langattoman tietoliikenteen maailmanlaajuista suosiota kiihdytti alun perin mahdollisuus korvata tietoliikennejärjestelmissä käytetyt kaapelit langattomilla ratkaisuilla. Ilmiö lisäsi myös tarvetta kehittää alan turvatekniikkaa monialaisen tutkimuksen pohjalta. Vaikka langattomat ratkaisut merkitsevät pienempiä asennuskustannuksia ja tarjoavat mahdollisuuksia luoda uudenlaisia palveluja, järjestelmien loppukäyttäjät edellyttävät kuitenkin niiden turvallisuuden olevan vastaavalla tasolla kuin langallisissa verkoissa. Myös teollisuuden langattomien tietoliikennejärjestelmen turvallisuus riippuu pitkälti viestintäkanavien turvallisuudesta. Väitöksen tavoitteena on kehittää uusia menetelmiä, joilla teollisuuden langattomat tietoliikennejärjestelmät voitaisiin turvata. Väitöksessä kehitetään toimenpiteitä tietoliikennejärjestelmien luottamuksellisuuteen ja koskemattomuuteen kohdistuvia hyökkäyksiä vastaan ja toteutetaan turvallisuusarviointi, joka kattaa järjestelmän protokollakerroksen sekä sähkömagneettisen ja fyysisen kerroksen. Väitöksen ensimmäisessä osassa hyödynnetään HIP–protokollaa (Host Identity Protocol) liikennevälineen sisäisen tietoliikennejärjestelmän turvallisuuden varmistamisessa. Lisäksi siinä kuvataan simulaatiot ja mittaushankkeet, joiden tavoitteena on arvioida käytetyn protokollan turvallisuusvaikutuksia esteettömän (line–of–sight, LOS) ja esteellisen (non–line–of–sight, NLOS) näköyhteyden tapauksissa. Sähkömagneettinen analyysi on tärkeä vaihe turvajärjestelmien kehitysprosessissa. Järjestelmissä käytetään yhä enemmän pieniä integroituja piirejä, mikä voi myös altistaa ne sähkömagneettisille (electromagnetic, EM) häiriöille. Väitöksessä tutkitaan lähikenttä–kaukokenttä -muunnokseen perustuvan arviointimenetelmän avulla sähkömagneettisen vuotosäteilyn tasoa. Lisäksi perehdytään testattavan laitteen (device under test, DUT) virtuaaliseen EM–liitäntään ja kuvataan, miten vastaavaa liitäntää voidaan hyödyntää palvelunestohyökkäyksissä. Väitöksessä tutkitaan myös tehokasta häirintämallia ja validoidaan teoreettisten laskelmien tulokset kokeellisesti. Lopuksi väitöksessä keskitytään tietoliikennejärjestelmän fyysisen kerroksen turvallisuuteen ja kehitetään kaksi algoritmia. Aktiivisen radiotaajuisen tunnistusmenetelmän avulla voidaan vaihtaa julkisia avaimia turvallista tietoliikenneyhteyttä muodostettaessa. Lisäksi esitellään vesileimausmenetelmään perustuva fyysisen kerroksen salausmenetelmä, WBPLSec. WBPLSec luo vastaanottimen ympärille suoja–alueen, minkä ansiosta se vaikuttaa analyysin ja tutkimustulosten perusteella olevan tehokas menetelmä toteuttaa fyysisen kerroksen suojaus.

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