UWB technology has been developing in imaging applications. For security imaging applications, it is vital to detect and image metallic targets concealed in bag at airports, subway stations or other public environments. To reduce the cost of the deployment of X-ray machines, a novel UWB imaging system has been developed, including the design of the UWB rotating antenna array, the design of RF circuits and the implementation of the two-dimensional delay-and-sum (DAS) image reconstruction method. Two types of UWB antennas, the circular-edge antipodal Vivaldi antenna and the corrugated balanced antipodal Vivaldi antenna (BAVA) have been designed and studied in both frequency domain and time domain. Both of them can work across UWB frequency range from 3.1 GHz to 10.6 GHz, and have directional radiation patterns. The corrugated BAVA with smaller physical size has been improved to have a relative high gain around 7 dBi across the operating frequency range. It also causes less distortion to signals in the time domain. So the corrugated BAVA is used as the antenna element in the UWB rotating antenna array. The UWB rotating antenna array comprises one central transmitting antenna and four receiving antennas. The receiving antennas, which rotate around the central transmitting antenna, are placed side-by-side on a straight arm. The equivalent antenna elements in space are increased by the rotation of the antenna array. The two-dimensional image reconstruction method has been developed based on DAS algorithm. This UWB imaging system can detect and reconstruct the image of the single and pairs of metallic targets concealed in bag. The smallest single target with the size of 4 cm × 4 cm × 1 cm can be reconstructed in images at a maximum distance of 30 cm away from the system. It can achieve 6 cm in cross-range resolution and 15 cm in down-range resolution. Therefore, the feasibility of the proposed UWB imaging system has been proved.

Many research groups have conducted the investigation into UWB imaging radar system for various applications over the last decade. Due to the demanding security requirements, it is desirable to devise a convenient and reliable imaging system for concealed weapon detection. Therefore, this thesis presents my research into a low cost and compact UWB imaging radar system for security purpose. This research consists of two major parts: building the UWB imaging system and testing the imaging algorithms. Firstly, the time-domain UWB imaging radar system is developed based on a modulating scheme, achieving a receiver sensitivity of -78dBm and a receiver dynamic range of 69dB. A rotary UWB antenna linear array, comprising one central transmitting antenna and four side-by-side receiving antennas, is adopted to form 2D array in order to achieve a better cross-range resolution of the target. In operation, the rotation of the antenna array is automatically controlled through the computerised modules in LabVIEW. Two imaging algorithms have been extensively tested in the developed UWB radar system for a number of scenarios. In simulation, the “Delay and Sum (DAS)” method has been shown to be effective at mapping out the metallic targets in free space, but prone to errors in more complicated environments. However, the “Time Reversal (TR)” method can produce better images in more complex scenarios, where traditionally unfavorable multi-path interference becomes a valuable asset. These observations were verified in experiment in different testing environments, such as penetration through wooden boards, clutters and a stuffed sport bag. The detectable size of a single target is 8×8×1 cm3 with 30cm distance in a stuffed bag, while DAS can achieve the estimation of 7cm cross-range resolution and 15cm down-range resolution for two targets with sizes of 8×8×1 cm3 and 10×10×1 cm3, which fits within the theoretical prediction. In contrast, TR can distinguish them with a superior 4cm cross range resolution.

Este trabalho apresenta um estudo sobre os principais sistemas de segurança utilizados em instalações elétricas automatizadas, com enfoque no controle de acesso físico, utilizando tecnologias biométricas. São apresentadas neste trabalho as principais características dos sistemas de segurança aplicados à detecção e combate de incêndios, ao controle do acesso físico, ao controle interno e externo da segurança, como circuitos fechados de televisão e controle de segurança perimetral, e as tecnologias biométricas que podem ser usadas para o controle de acesso de pessoas. É apresentado o desenvolvimento de um protótipo de baixo custo, utilizando tecnologia biométrica para o controle de acesso físico, assim como as principais vantagens e desvantagens, algoritmos e relações custo-benefício para o uso de biometria em sistemas de segurança. O estudo mostra que o uso da biometria como ferramenta para a melhoria dos sistemas de segurança existentes é uma tendência mundial, no entanto, existe uma preocupação crescente sobre a confidencialidade das informações biométricas das pessoas. / This work presents a study of the main security systems used in automatized electric installations, with approach in the physical access control, using biometric technologies. The main characteristics of the security systems applied to the detection and fire combat, to the physical access control, to the internal and external security control, as closed-circuits television and perimetral security control, and the biometric technologies are presented in this work that can be used for the people access control. The development of a low cost prototype is presented, using biometric technology for the physical access control, as well as the main advantages and disadvantages, algorithms and cost-benefit relations for the use of biometry in security systems. The study shows that the use of the biometry as tool for the existing security systems improvement is a world-wide trend, however, an increasing concern exists of the people biometric information confidentiality.

Thesis (MTech (Information Technology))--Cape Peninsula University of Technology, 2018. / In today’s world, organisations cannot exist without having information readily available. The protection of information relies not only on technology but also on the behaviour of employees. The failure to institutionalise an information security culture inside an organisation will cause the continued occurrence of security breaches. The aim of the research is to explore how an information security culture can be institutionalised within a petroleum organisation in the Western Cape. The primary research question is posed as follows: “What are the factors affecting the institutionalisation of an information security culture?” To answer the research question, a study was conducted at a petroleum organisation in the Western Cape. A subjectivist ontological and interpretivist epistemological stance has been adopted and an inductive research approach was followed. The research strategy was a case study. Data for this study were gathered through interviews (12 in total) using semi-structured questionnaires. The data collected were transcribed, summarised, and categorised to provide a clear understanding of the data. For this study, twenty-four findings and seven themes were identified. The themes are: i) user awareness training and education; ii) user management; iii) compliance and monitoring; iv) change management; v) process simplification; vi) communication strategy; and vii) top management support. Guidelines are proposed, comprising four primary components. Ethical clearance to conduct the study was obtained from the Ethics committee of CPUT and permission to conduct the study was obtained from the Chief Information Officer (CIO) of the petroleum organisation. The findings point to collaboration between employees, the Information Security department, and management in order to institute a culture of security inside the organisation.

Mini-thesis submitted in fulfilment of the requirements for the Degree of Masters of Management in the field of Security (MM-S) In the Graduate School of Public and Development Management University of Witwatersrand February 2017 / This is a report on Security Vetting in the Department of Home Affairs. The South African Public Service (including the Department of Home Affairs) as an employer has an obligation to deliver services in an accountable and transparent manner and because of that people who obtain employment in the public sector are expected to possess a high level of integrity and professional ethics. The Security Screening Investigation (SSI) commonly known as Security Vetting or Vetting was introduced in government departments with the objective of ensuring that all the individuals employed in government with access to classified information possess the qualities that will enable them “not to cause classified information or material to fall into unauthorised hands, thereby harming or endangering the security and/or interests of the State”. The process of vetting is, however, the mandate of the State Security Agency (SSA), with the responsibility of a larger portion of the vetting process while the smaller portion of the function lies with some government departments, of which the DHA is one. It has been observed that regardless of the decentralization of the functions of vetting by the SSA, there are still challenges that are experienced in DHA with the current vetting approach/strategy. This study was undertaken with the purpose of identifying and describing the challenges relating to the current vetting process in the DHA and as a follow-up to determine the possibility of establishing a strategy that will address the current shortcomings. Interviews were undertaken with Home Affairs officials to collect data on the effectiveness and efficiency of the current vetting strategy in the department, the challenges and the shortcomings concerning vetting, as well as how vetting strategy can be constructed in order to alleviate the challenges and the shortcomings. The findings indicate that the current vetting strategy is neither effective nor efficient. The report further indicates that there are several challenges with the current vetting strategy in DHA, such as DHA reliance on SSA for the completion of the vetting process, a shortage of vetting officers in the department, delayed turnaround times on the conclusion of the vetting process as well as failure in the implementation of the vetting strategy. The conclusion is that the current vetting strategy needs to be reviewed and improved. / MT2017

Thèse doctorat : Informatique : Villeurbanne, INSA : 2006. / Thèse rédigée en anglais. Titre provenant de l'écran-titre. Bibliogr. p. 88-98.

Magistriniame darbe išanalizuoti įvairios paskirties saugos modeliai. Pagal gautus rezultatus sudarytas apibendrintas informacijos saugos praradimo riziką įvertitnantis kompiuterių tinklų saugos modelis. Sukurta grėsmę keliančius įvykius aptinkanti sistema. / The master's work analysis different types of security models. It also proposes a new computer network security reference model, which includes risk management process. A suspicious network events detection system is designed to make network monitoring easier.

This research proposes a framework for adaptive information security systems that considers both the technical and social aspects of information systems security. Initial development of information systems security focused on computer technology and communication protocols. Researchers and designers did not consider culture, traditions, ethics, and other social issues of the people using the systems when designing and developing information security systems. They also seemed to ignore environments where these systems run and concentrated only on securing parts of the information systems. Furthermore, they did not pay adequate attention to the enemies of information systemsand the need for adaption to a changing enviroment. The consequences of this lack of attentions to a number of important factors have given us the information security systems that we have today, which appear to be systemically insecure.   To approach this systemic insecurity problem the research was divided into mini studies that were based on the Systemic-Holistic paradigm, Immune System concepts, and Socio-Technical System theory. Applying the holistic research process the author started first by exploring adaptation systems. After exploring these systems, the focus of the research was to understand the systems and features required for making information security systems learn to adapt to the changing environments. Designing and testing the adaptive framework were the next steps. The acquired knowledge from this research was structured into domains in accordance to ontological principles and relationship between domains was studied. These domains were then integrated with the security value-based chain concept, which include deterrence, prevention, detection, response, and recovery functions to create a framework for adaptive information security systems.   The results of the mini studies were reported in a number of papers, which were published in proceedings of international conferences and a journal. For this work, 12 of the thesis papers are included. A framework for adaptive information security system was created. Trials to apply and validate the framework were performed using three methods. The first method was a panel validation, which showed that the framework could be used for providing adaptive security measures and structuring  security work. The second method mapped the framework to the security standards, which showed that the framework was aligned with the major information systems security standards. The third and last validation method was to map the framework with reported ICT crimes cases. The results indicated that most crimes appear to occur because the security systems in place lacked deterrence security measures and had weak prevention, detection, and response security measures. The adaptive information security systems framework was also applied to a number of areas including a secure e-learning, social networks, and telemedicine systems.   It is concluded in this thesis that this adaptive information security system framework can be applied to minimize a number of  systemic insecurity problems and warrants more applied research and practical implementations. / Q 20110608

Thesis (M. Sc.) (Hons.) -- University of Western Sydney, Nepean, 1999. / Thesis submitted in fulfilment of the requirements for the award of the degree Master of Science (Honors) from the University of Western Sydney, Nepean, School of Computing and Information Technology. Bibliography : p. 87-88.

Thesis (Ph.D.)--University of Wollongong, 2007. / Typescript. Includes bibliographical references: p. 172-198.