7 research outputs found
The design of a defence mechanism to mitigate the spectrum sensing data falsification attack in cognitive radio ad hoc networks
No full textThesis ( M.Sc. ( Computer Science)) -- University of Limpopo, 2018Dynamic spectrum access enabled by cognitive radio networks is envisioned to address the problems of the ever-increasing wireless technology. This innovative technology increases spectrum utility by allowing unlicensed devices to utilise the unused spectrum band of licenced devices opportunistically. The unlicensed devices referred to as secondary users (SUs) constantly sense the spectrum band to avoid interfering with the transmission of the licenced devices known as primary users (PUs).Due to some environmental challenges that can interfere with effective spectrum sensing, the SUs have to cooperate in sensing the spectrum band. However, cooperative spectrum sensing is susceptible to the spectrum sensing data falsification (SSDF) attack where selfish radios falsify the spectrum reports. Hence, there is a need to design a defence scheme that will defend the SSDF attack and guaranty correct final transmission decision.
In this study, we proposed the integration of the reputation based system and the qout-of-m rule scheme to defend against the SSDF attack. The reputation-based system was used to determine the trustworthiness of the SUs. The q-out-of-m rule scheme where m sensing reports were selected from the ones with good reputation and q was the final decision, which was used to isolate the entire malicious nodes and make the correct final transmission decision. The proposed scheme was implemented in a Cognitive Radio Ad Hoc Network (CRAHN) where the services of a data fusion centre (FC) were not required. The SUs conducted their own data fusion and made their own final transmission decision based on their sensing reports and the sensing reports of their neighbouring nodes. Matlab was used to implement and simulate the proposed scheme. We compared our proposed scheme with the multifusion based distributed spectrum sensing and density based system schemes. Metrics used were the success probability, missed detection probability and false alarm probability. The proposed scheme performed better compared to the other schemes in all the metrics.CSIR,
NRF and,
University of Limpopo research offic
The design of a defence mechanism to mitigate the spectrum sensing data falsification attack in cognitive radio ad hoc networks
No full textTrust-Based System to Defend Against the Spectrum Sensing Data Falsification Attack in Cognitive Radio Ad Hoc Network
No full textOtherness and identity in cinematographic fiction in Portugal and in Mozambique
No full textTese de doutoramento em Estudos CulturaisA presente tese visa compreender as representações identitárias veiculadas pelo cinema ficcional, em Portugal e em Moçambique, e como são negociadas por públicos de ambos os países. Mais especificamente, trata-se de perceber os modelos dominantes de representação de “nós” e do “outro” em longas-metragens de ficção de ambos os países, e posteriormente perceber como são discutidos por públicos portugueses e moçambicanos, filmes estreados entre 2006 e 2015. Durante este processo, descortina-se também a capacidade que o cinema contemporâneo revela, ou não, de propor imagens alternativas (aos referidos modelos dominantes) do “outro” africano/europeu. É levada a cabo uma aproximação ao Filme, nos dois países, em três etapas: analisa-se a construção das cinematografias, a circulação de Poder entre ambas e, mais especificamente, as formas de representação do “nós” na relação com um “outro”, sobretudo depois de 1975, porém considerando os legados anteriores. Depois, analisa-se o percurso e o discurso de autores específicos, sobre o cinema, os meios de produção, os regimes políticos e contextos internacionais, privilegiando o contributo dos cineastas, mas também o da crítica especializada e a legislação. Nesta fase, além de considerada globalmente a obra de cada autor, aprofundase a reflexão sobre um filme particular. Por fim, tendo como base discussões promovidas especificamente para esta investigação, analisa-se o discurso de públicos não especializados, em ambos os países, sobre o corpo fílmico selecionado. A reflexão que este trabalho constitui encontra uma profunda e pesada herança discursiva do passado colonial – ainda que por oposição, ou negação - tanto nos discursos fílmicos ao longo do tempo e no momento presente, como nas relações entre as culturas cinematográficas Portugal/Moçambique, ou Norte/Sul, como ainda nos diálogos que espectadores, de ambos os países, estabelecem com as obras e com um “outro” africano ou europeu. O cinema que ensaia contrapor discursos alternativos aos modelos hegemónicos comunica dificilmente com públicos não especializados e esta dificuldade é agravada pelo desinteresse mútuo (Portugal/Moçambique) a que ambas as cinematografias são votadas.This thesis aims at analysing the identity representations conveyed by fictional cinema, in Portugal and in Mozambique, and how they are negotiated by public of both countries. More specifically, it is intended to perceive the dominant representation models of "we" and "other" in feature films from both countries, and later on, to understand how films released between 2006 and 2015 are discussed by Portuguese and Mozambicans publics. During this process, is also possible to uncover the capacity that contemporary cinema reveals, or not, to propose alternative images (to the mentioned dominant models) of the African / European "other". An approximation to the study of Film in both countries is carried out in three stages: the construction of this cinematography, the circulation of power between the two, and, more specifically, the forms of representation of the "we" in relation with an "other", especially after 1975, but considering the previous legacy. Then, the course and the discourse of specific authors, about cinema, the means of production, the political regimes and international contexts, focusing on the contribution of the filmmakers, but also specialized criticism and legislation, are analysed. In this phase, in addition to being considered globally the work of each author, the reflection on a particular film is deepened. Finally, based on discussions promoted specifically for this research, is analysed the discourse of non-specialized audiences in both countries on the selected filmic body. The reflection that this work constitutes finds a deep and heavy discursive heritage of the colonial past - albeit by opposition, or denial - both in the filmic discourses throughout time and in the present moment, as in the relations between the cinematographic cultures Portugal/Mozambique, or North/South, as well as in the dialogues that spectators from both countries establish with the works and with an African or European "other". When Film tries to propose alternative discourses to hegemonic models hardly communicates with nonspecialized audiences and this difficulty is aggravated by the mutual disinterest (Portugal / Mozambique) to which both filmographies are voted
The joy at the Last Judgement according to the Heidelberg Catechism Question 52
No full textIn this contribution, the author reflects on Question 52 of the Heidelberg Catechism where it asks: ‘What comfort is it to you that Christ “shall come to judge the living and the dead”?’ The author points out possible sources from which this formulation stems, that is, Articles 86 and 87 in John Calvin’s Catechism from 1545. God is described as a compassionate judge. Even more: the One who is the last judge, was also judged and had paid for our sins. In a dialectical fashion we discover a God who is just, but also merciful. The Reformed tradition did not follow a dead-end where it is taught that God shows us grace instead of righteousness. Had God proceeded in this way, he would only mean things well, but he would not make them well. The realisation of God being just and merciful leads to joy and repentance. The contribution ends with a discussion of the final separation of the just and evil
Kanova e o segredo da caveira, de Pedro Pereira Lopes: adaptação na linguagem dos quadrinhos
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Programa de Pós-Graduação em Estudos da Tradução, Florianópolis, 2022.A pesquisa tem como objeto de estudo o livro para a infância Kanova e o segredo da caveira, do escritor moçambicano Pedro Pereira Lopes, cujo objetivo é desenvolver uma adaptação para a linguagem dos quadrinhos, a fim de promover a divulgação e o acesso à obra do autor por meio de uma nova versão. Para isso parte-se da síntese do livro em questão que se insere na categoria de literatura africana de língua portuguesa para infância. Desse modo, a dissertação estabelece relações dialógicas com os estudos da tradução e da adaptação, com a temática das histórias em quadrinhos, com a Lei 10639/2003, além das culturas africanas, com destaque para a de Moçambique. A fundamentação teórica da tradução reúne as teorizações de Cristiane Nord (2016), Ricoeur (2012) Debus e Torres (2016), Plaza (2003), entre outros. No que diz respeito à adaptação se utiliza o referencial apresentado por Hutcheon (2013), Carvalho (2014), Galvão e Nazaro (2017), no que se refere à literatura moçambicana, as ideias inseridas no texto da dissertação são desenvolvidas a partir de Fonseca e Moreira (2007), Oliveira (2014), Debus (2018, 2020, 2021), Lopes (2017, 2020), Noronha (2020), Nataniel Ngomane (2020); sobre a literatura africana e a Lei 10639/2003 destacam-se as abordagens vinculadas por Pereira (2010), além de discussões construídas por Muller (2013), Fonseca (2015), Debus (2017), Moreira (2018), Bernardes (2018); no que se trata do assunto da literatura infantil brasileira tem-se como base teórica o ponto de vista de Coelho (1991, 1996), Lajolo e Zilberman (1999), Lajolo (1989); em relação as histórias em quadrinhos, apoia-se nos enunciados de Calazans (2008), Iannone (1994), Pina (2014), Santos e Silvia (2015), Neto e Silva (2015), Teixeira (2015), Pimentel (2018) e, finalmente, para produzir um texto adaptado para a linguagem dos quadrinhos leva-se em conta as orientações de Bortoni (2011), Danton (2000), Scott McCloud (1995, 2008) entre outros. Todas essas informações reunidas ao longo da pesquisa resultaram em um trabalho acadêmico teórico e prático (uma adaptação para os quadrinhos do livro Kanova e o segredo da caveira que ao ganhar um formato de revista, poderá servir como instrumento pedagógico).Abstract: This research has as an object of study the book for children Kanova e o segredo da caveira, by the Mozambican writer Pedro Pereira Lopes, with the objective of developing an adaptation to the language of comics, in order to promote the dissemination and access to the narrative of the author through a new version. For this purpose, we start from the synthesis of the book in question which is inserted into African literature of Portuguese language for childhood category. Therefore, this thesis establishes dialogic relationships with the studies of translation and adaptation, with the theme of comics, with Law 10639/2003 and with African cultures, especially the culture of Mozambique. The theoretical foundation of translation brings together the theories of Cristiane Nord (2016), Ricoeur (2012), Debus and Torres (2016), Plaza (2003), among others; with regard to adaptation, the reference presented in this research by Hutcheon (2013), Carvalho (2014), Galvão and Nazaro (2017). Regarding to Mozambican literature, the ideas inserted in the text of this study are developed from the thinking of Fonseca and Moreira (2007), Oliveira (2014), Debus (2018, 2020, 2021), Lopes (2017, 2020), Noronha (2020), Nataniel Ngomane (2020); on African literature and Law 10639/2003, the approaches are linked by Pereira (2010), as well as discussions built by Muller (2013), Fonseca (2015), Debus (2017), Moreira (2018), Bernardes (2018); when it comes to the subject of Brazilian children's literature, the theoretical basis is the point of view of Coelho (1991, 1996), Lajolo and Zilberman (1999), Lajolo (1989); in relation to comics, it is based on statements by Calazans (2008), Iannone (1994), Pina (2014), Santos and Silvia (2015), Neto and Silva (2015), Teixeira (2015), Pimentel (2018) ) and, finally, to produce a text adapted to the language of comics, the guidelines of Bortoni (2011), Danton (2000), Scott McCloud (2008) among others are taken into account. All the information was collected during the research which resulted in a theoretical and practical academic work (an adaptation to the comic book Kanova e o segredo da caveira that, when it gains a magazine format, can serve as a pedagogical tool)
Hidden victims of HIV/AIDS : the impact of caregiving on elderly caregivers
No full textIncludes bibliographical references (leaves 92-107).The HIV/AIDS pandemic in South Africa and the concomitant high mortality rate of the middle generation has resulted in an increased number of orphans and vulnerable children (DVCs). The responsibility of care for these children has fallen to the extended family, especially elderly females. This study aimed to explore the impact of caregiving on grandmothers caring for DVCs in two Western Cape townships, and to statistically determine predictors of caregiver burden. Participants (n = 57) were members of a community-based supportive organisation, were grandmother caregivers to at least one grandchild, and lived in a household that was impacted by HIVI AIDS. A quantitative questionnaire, consisting of socio-demographic questions, as well as open-ended questions on participants' experiences within the organisation and of caregiving, was individually administered in Xhosa. The Burden Interview (BI), a standardised scale, was used to measure the impact of caregiving on the grandmothers across five dimensions (health, finances, psychological well-being, social life, and relationships). Descriptive statistical analysis of the socio-demographic questionnaire showed that caregiving occurred in the context of poverty, HIV/AIDS, chronic illness, and multigenerational households. Thematic analysis of the open-ended questions revealed that participants benefited financially and emotionally and gained knowledge and skills through membership of the community organisation. However, caregiving was commonly described as emotionally and physically exhausting. This burden was exacerbated by the age and health status of both caregiver and care-recipient, and behavioural difficulties in the care-recipient. A stepwise multiple regression analysis yielded three factors as significant predictors of burden (Rl = .41): the number of children for which the participant was the primary caregiver; the number of chronically ill people in the household; and the need for assistance with caregiving responsibilities. The latter finding probably implies that those who are the most stressed are most likely to require assistance with care. The findings highlight the important contribution of the elderly in buffering the psychosocial impact of the HIV/AIDS pandemic, sometimes at the expense of their own wellbeing. Policy-makers should consider the unique challenges and contributions of the elderly in this regard
