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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.
1

An experimental investigation of the sensitivity of a buried fiber optic intrusion sensor

Kuppuswamy, Harini 12 April 2006 (has links)
A distributed fiber optic sensor with the ability of detecting and locating intruders on foot and vehicles over long perimeters (>10 km) was studied. The response of the sensor to people walking over or near it and to vehicles driving nearby was observed and analyzed. The sensor works on the principle of phase sensitive optical time domain re ectometry, making use of interferometric effects of Rayleigh backscattered light along a single mode fiber. Light pulses from a highly stable Er:doped fiber laser emitting single longitudinal mode light and exhibiting low frequency drift are passed through one end of the buried fiber. The backscattered light emerging from the same fiber end was monitored using a photodetector. The phase changes produced in the light pulse due to the pressure of the intruder walking directly above or near the sensor or from the seismic disturbances created by vehicles moving in the vicinity of the sensor are detected using the phase sensitive Optical Time Domain Re ectometer (OTDR). Field tests were conducted with the sensing element as a single mode fiber in a 3-mm diameter cable buried at depths ranging from 8 to 18 inches in clay soil. It was observed that the sensor could detect intruders walking transverse to the cable line at a distance of 40 ft from it. A car moving at a speed of 30 mph on a rough road could be consistently detected up to a distance of 480 ft from the sensor, while a car driven on a smooth road 200 ft from the sensor could be detected only when passing through rough patches on the road. Tests were also performed with an intruder walking near the sensor while a car was driven at a speed of 30 mph on a rough road. The effect on the signal due to the intruder on foot could be distinguished clearly only when the car was at least 200 ft away from the sensor. The results in this thesis represent the first quantitative study of the sensitivity of the sensor under varied test conditions. It is expected that these findings will be helpful in the practical implementation of the long perimeter intrusion sensor along high security domains like national borders, military bases and government buildings.
2

Statistical and Fuzzy Set Modeling for the Risk Analysis for Critical Infrastructure Protection

Cotellesso, Paul 25 September 2009 (has links)
No description available.
3

Distributed fiber optic intrusion sensor system for monitoring long perimeters

Juarez, Juan C. 02 June 2009 (has links)
A distributed sensor using an optical fiber for detecting and locating intruders over long perimeters (>10 km) is described. Phase changes resulting from either the pressure of the intruder on the ground immediately above the buried fiber or from seismic disturbances in the vicinity are sensed by a phase-sensitive optical time-domain reflectometer (φ−OTDR). Light pulses from a cw laser operating in a single longitudinal mode and with low (MHz/min range) frequency drift are injected into one end of the single mode fiber, and the backscattered light is monitored with a photodetector. In laboratory tests with 12 km of fiber on reels, the effects of localized phase perturbations induced by a piezoelectric fiber stretcher on φ−OTDR traces were characterized. In field tests in which the sensing element is a single mode fiber in a 3-mm diameter cable buried in an 8 to 18 inch deep, 4 inch wide trench in clay soil, detection of intruders on foot up to 15 ft from the cable line was achieved. In desert terrain field tests in which the sensing fiber is in a 4.5-mm diameter cable buried in a 1 ft deep, 2.5 ft wide trench filled with loose sand, high sensitivity and consistent detection of intruders on foot and of vehicles traveling down a road near the cable line was realized over a cable length of 8.5 km and a total fiber path of 19 km in real time. In a final series of field tests in clay soil, phase changes produced by the steps of a person walking up to 15 ft away from the buried cable were observed, and vehicles traveling at 10 mph were consistently detected up to 300 ft away. Based on these results, this technology may be regarded as a candidate for providing low-cost perimeter security for nuclear power plants, electrical power distribution centers, storage facilities for fuel and volatile chemicals, communication hubs, airports, government offices, military bases, embassies, and national borders.
4

Distributed fiber optic intrusion sensor system for monitoring long perimeters

Juarez, Juan C. 02 June 2009 (has links)
A distributed sensor using an optical fiber for detecting and locating intruders over long perimeters (>10 km) is described. Phase changes resulting from either the pressure of the intruder on the ground immediately above the buried fiber or from seismic disturbances in the vicinity are sensed by a phase-sensitive optical time-domain reflectometer (φ−OTDR). Light pulses from a cw laser operating in a single longitudinal mode and with low (MHz/min range) frequency drift are injected into one end of the single mode fiber, and the backscattered light is monitored with a photodetector. In laboratory tests with 12 km of fiber on reels, the effects of localized phase perturbations induced by a piezoelectric fiber stretcher on φ−OTDR traces were characterized. In field tests in which the sensing element is a single mode fiber in a 3-mm diameter cable buried in an 8 to 18 inch deep, 4 inch wide trench in clay soil, detection of intruders on foot up to 15 ft from the cable line was achieved. In desert terrain field tests in which the sensing fiber is in a 4.5-mm diameter cable buried in a 1 ft deep, 2.5 ft wide trench filled with loose sand, high sensitivity and consistent detection of intruders on foot and of vehicles traveling down a road near the cable line was realized over a cable length of 8.5 km and a total fiber path of 19 km in real time. In a final series of field tests in clay soil, phase changes produced by the steps of a person walking up to 15 ft away from the buried cable were observed, and vehicles traveling at 10 mph were consistently detected up to 300 ft away. Based on these results, this technology may be regarded as a candidate for providing low-cost perimeter security for nuclear power plants, electrical power distribution centers, storage facilities for fuel and volatile chemicals, communication hubs, airports, government offices, military bases, embassies, and national borders.
5

Diseño de arquitectura de seguridad perimetral para una empresa dedicada a la actividad inmobiliaria

Montes Larios, Jose Manuel, Iturrizaga Hernández, Manuel Antonio January 2015 (has links)
Debido a que el uso de Internet se encuentra en aumento, cada vez más compañías permiten a sus socios y proveedores acceder a sus sistemas de información. Por lo tanto, es fundamental saber qué recursos de la compañía necesitan protección para así controlar el acceso al sistema y los derechos de los usuarios del sistema de información. A su vez día a día se descubren nuevas vulnerabilidades, nuevos tipos de ataques y nuevos parches que aplicar los sistemas institucionales, convirtiendo la operación de la seguridad en una tarea sumamente compleja y demandante. El presente documento es sobre el desarrollo de la seguridad perimetral en la empresa Los Portales, vale indicar que dicha empresa es una de las más renombradas a nivel de la actividad inmobiliaria en el Perú, por ende se está considerando las amenazas de seguridad desde perspectivas diferentes para permitir de esta forma conocer algunos riesgos que puedan afectar a la institución, así como determinar el nivel de madurez de la seguridad informática, a su vez se demostrara a detalle el diseño e implementación de la solución así como el alcance económico. Because Internet use is increasing, more and more companies allow their partners and suppliers access to their information systems. Therefore, it is essential to know what company resources need protection so as to control system access and the rights of users of the information system. In turn every day new vulnerabilities, new types of attacks and new patches to apply institutional systems, making the security operation in an extremely complex and demanding task are discovered. This thesis is on the development of perimeter security at Los Portales, it indicate that the company is one of the most renowned level of real estate activity in Peru, thus being considered security threats from different perspectives to meet thus enable some risks that may affect the institution, and to determine the maturity level of computer security, in turn demonstrate in detail the design and implementation of the solution as well as the economic scope.
6

An examination of the impact of residential security measures on the incidence of residential burglary in two selected northern suburbs of Johannesburg: a security risk management approach

Olckers, Casparus 30 June 2007 (has links)
Motivation This project was of specific importance to the private security industry, victims of residential burglary, community policing forums and the South African Police Service in providing detailed information regarding recommendations of how to manage and combat residential burglary in two selected northern suburbs of Johannesburg. Problem statement Residential burglary is categorised in the top three highest reported crimes according to the official South African Police Service statistics for the 2006/7 financial years. A series of victim interviews, docket analysis, case plotting and residential security audit surveys were conducted to determine the extent (or lack thereof) of security measures at a burgled residence in the selected area. Approach Field data was collected through docket analysis, plotting crime scenes (descriptive mapping), victim interviews and residential security audit surveys. Results The majority of victims of burglary interviewed did not have the minimum security system (integrated measures) in place. Those victims, who had security measures, appeared not to have made or implemented effective use of them. Conclusion Security at a residence extends beyond just the immediate house area and the focus (security risk assessment) should start with the immediate neighbourhood (community) area working inwards towards the property perimeter (boundary), inner perimeter (garden area) and then finally the immediate house area. / CRIMINOLOGY / MTECH: SECURITY RISK MAN
7

An examination of the impact of residential security measures on the incidence of residential burglary in two selected northern suburbs of Johannesburg: a security risk management approach

Olckers, Casparus 30 June 2007 (has links)
Motivation This project was of specific importance to the private security industry, victims of residential burglary, community policing forums and the South African Police Service in providing detailed information regarding recommendations of how to manage and combat residential burglary in two selected northern suburbs of Johannesburg. Problem statement Residential burglary is categorised in the top three highest reported crimes according to the official South African Police Service statistics for the 2006/7 financial years. A series of victim interviews, docket analysis, case plotting and residential security audit surveys were conducted to determine the extent (or lack thereof) of security measures at a burgled residence in the selected area. Approach Field data was collected through docket analysis, plotting crime scenes (descriptive mapping), victim interviews and residential security audit surveys. Results The majority of victims of burglary interviewed did not have the minimum security system (integrated measures) in place. Those victims, who had security measures, appeared not to have made or implemented effective use of them. Conclusion Security at a residence extends beyond just the immediate house area and the focus (security risk assessment) should start with the immediate neighbourhood (community) area working inwards towards the property perimeter (boundary), inner perimeter (garden area) and then finally the immediate house area. / CRIMINOLOGY / MTECH: SECURITY RISK MAN

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