This research examined a heat transfer model to predict the activation time of a concealed sprinkler. Concealed sprinklers consist of two stages of activation. They include the release of cover plates from a recess housing and the breakage of the glass bulbs or melting of the solder links. The research analysis is divided into two sections. The first section includes the prediction of cover plate activation time (stage one) and the second section includes the prediction of glass bulb activation time (stage two). Each prediction result is compared with the experimental data conducted by Annable (2006) and Yu (2007). A lumped heat capacity method is introduced to predict the activation time of the cover plate. This method has been used for predicting the activation time of a standard pendent exposed sprinkler. It is reasonable to apply this method by assuming they are flush with the ceiling. The analysis results are compared based on the percentage of predicted and measured uncertainties. A recommendation is provided for which method is appropriate to apply to predicting the cover plate activation time. The proposed of using FDS5 simulations is to simulate the heat transfer to the sensing element (glass bulb only) within the recessed housing. The constructed simulation models comprises of ceiling within a compartment. The simulations of various sprinkler heads are performed to investigate any parameters that can potentially affect the activation time of the sprinklers. To simulate the glass bulb, combined thermal properties including glass and glycerine are modified to account for the differences in mass. Prior to stage two analysis, the FDS5 simulation was tested to predict the activation time of a standard pendent exposed sprinkler. The results showed positive progress to carry onto the next analysis. In stage two analysis, the simulations are constructed with and without the presence of vent holes within the recess housing. The combined activation time for concealed sprinklers show lack of solid predictions compared to the experimental data especially Yu experimental data.

Existing weapon detection systems such as metal detectors and X-ray baggage scanners have many drawbacks. While metal detectors can only detect metallic objects, X-ray scanners are unsafe for use on passengers. Also, these systems can only scan people within a short range. These limitations of detecting potentially harmful objects have led to tragic events such as the 9/11 attack on the world trade centre and the 2008 terrorist attack in Mumbai. Development of more advanced security systems would help in curbing such terrorist attacks. These systems could also be used to help security officials in tackling knife and gun related crimes in the streets. The aim of this research is to develop a concealed weapon detection system using acoustic waves. Ideally, the system would have large standoff distance, should be cost-effective and easy to manufacture and would be able to detect both metal and non-metallic weapons. Different techniques such as acoustic signature, resonance acoustic spectroscopy and acoustic imaging were analysed. Acoustic signature techniques identify the target by comparing the acoustic waves reflected by the target to a database of previously recorded acoustic reflections. Resonance acoustic spectroscopy was used on the data acquired using both experimental measurements and Finite Element simulations. A series of resonant frequencies from the acoustic waves reflected by the concealed target were extracted using this technique. This series of resonant frequencies that are unique to the target were used to identify the target. Acoustic camera was used to experimentally record the acoustic reflection from different targets. This was then used to develop images of concealed targets. These tests were performed using commercially available array speaker systems. The probability of improving these results using a better designed ultrasonic or acoustic array speaker system was analysed. This was done by changing different array design parameters and obtaining a highly focused acoustic beam. The results from the experimental tests and Finite Element simulations proved the possibility of using acoustic waves for concealed weapon detection. In the acoustic signature measurements, the frequency spectra of the reflected acoustic waves were shown to be different for different targets. The results from resonance acoustic spectroscopy showed structural resonant frequencies in the frequency spectra that corresponded to the natural frequency of the target. Using acoustic camera kit the image of the concealed target was identified. The array results showed the formation of focused beams for different array configurations. The results showed the formation of grating lobes and side lobes when the inter-element gap became larger than the wavelength of sound waves at the excitation frequency. Finally, a program using neural network was developed to demonstrate how the natural frequencies from the target could be used to identify them. This research work provides a proof of concept of different acoustic wave-based detection and imaging techniques. It has shown the possibility of detecting concealed targets at standoff distances. Using parametric arrays highly focused acoustic or ultrasonic beams could be generated which could be focused on a person suspected of carrying a weapon in a crowded environment. The sound waves reflected back could be analysed using the resonance acoustic spectroscopic technique or one could use the acoustic camera to generate images of targets in real-time. The use of acoustic waves would also help in keeping the cost and complexity of the equipment to a minimum. It also ensures that the public is not exposed to any harmful radiation. The techniques described in this thesis would significantly support the development of a commercially viable, robust acoustic waves based concealed weapon detection system.

The carrying of concealed weapons for protection, specifically handguns, is a widely debated topic. This is especially true on college campuses following highly publicized mass shooting events. Researching students’ projected carrying behavior if legal on campus is important because it sheds light on the extent to which a concealed carry policy would be utilized in the university context, which has implications for public safety as well as student perceptions of safety. The scholarly literature indicates that White, Southern males who own guns are most likely to favor concealed carry policies. Donald Black’s theory of self-help (1983) and the collective security hypothesis (1987) frame this investigation by exploring whether students who feel that local law enforcement is ill equipped to protect them are more likely to say that they would utilize a concealed carry policy on campus as a measure of self-protection. Analyzing survey data from a Midwestern university In the Spring of 2009 with logistic regression, it is clear that the majority of students sampled are not in favor of a policy for carrying concealed firearms onto campus. As expected males and gun owners are significantly more likely to say they would carry concealed if legal. The interaction between gender and trust in law enforcement is also significant, indicating that males are more likely to say they would carry on campus relative to females as their level of confidence in law enforcement decreases. Overall, this research does not support Donald Black’s theory of self-help and the collective security hypothesis. In order to better test the theory of self-help and the collective security hypothesis, additional measures of the key variables are warranted in future research. In addition conducting a survey on projected carrying behavior with a nationally representative sample would aid understanding as to how the broader population of students in The United States would feel and behave if concealed carry were legal on their campus. Further investigation exploring why gender and law enforcement interact in predicting projected carry behavior is warranted.

Abstract: This dissertation explores how cultural meanings around race, class, and gender shape concealed handgun licensing in Texas. This project utilizes in-depth interviews with 36 concealed handgun license holders and field observations at licensing courses and gun ranges to understand why people get a license, what their gun carrying practices are, and how they imagine criminal threat and self-defense. Through my analysis of interviews, I find that masculinity is central to how men become gun users and why they want to obtain a concealed handgun license. Women explain their desire for a CHL as rooted in feelings of empowerment. While traditional conceptions of “fear of crime” are not a motivating factor for most of the license holders I interviewed, I find that CHL holders feel vulnerable to potential crime because they assume that criminals are armed. These interviews also suggest that perceptions of criminality are highly racialized, as predominantly black spaces are marked as threatening. As I argue, part of the appeal of concealed handgun licenses is that they signify to those who have them that they are the embodiment of personal responsibility. / text

Installation of exposed fire sprinklers may cause inconvenience in areas where architectural and interior presentation is significant. In order to overcome this inconvenience, recessed and concealed sprinklers were created and are applied widely. Response Time Index (RTI) and C-factor are the thermal sensitivity (intrinsic parameters) used to characterise a sprinkler. They are also used as input parameters in computer fire models to simulate sprinkler response time. However, the RTI and C-factor are not published by the manufactures. Therefore the RTI and C-factor of the recessed and concealed sprinklers have been analysed and determined in this research. In order to obtain the RTI of the recessed and concealed sprinklers, four of the most commonly used sprinkler models (two recessed and two concealed) in New Zealand have been investigated in plunge test experiment by using a wind tunnel in this research. The UC3 wind tunnel used to conduct the plunge test has been fabricated in this research. This work has demonstrated that the UC3 wind tunnel could provide a very stable and uniform temperature profile in the test section. However, the velocity uniformity of the tunnel needs to be improved in the future. The "apparent" RTI for different recessed and concealed sprinkler models (two recessed and two concealed) have been determined in the plunge test experiment. It should be noted that the "final calculated RTI" for each tested recessed and concealed sprinklers has been denoted as "apparent RTI" in this study. BRANZFIRE computer model has been used to model the fire scenarios in the full scale fire tests conducted by Bill and Heskestad (1995). The best input fire object location, the best input sprinkler distance below the ceiling and the input "apparent C-factor" in BRANZFIRE for the flush, recessed, concealed and the recessed sidewall sprinklers have been determined in this research. This work has generally improved the guidance available to fire safety engineers for the RTI and C-factor of the recessed and concealed sprinklers.

School and campus shootings are a contemporary problem in the United States. Because of these shootings, colleges have enacted new policies to ensure safety on their campuses, including concealed carry on campus. The State of Tennessee has a unique law in place that allows colleges to create their own policies regarding concealed carry on campus, with the stipulation that only full-time faculty and staff can carry concealed weapons. East Tennessee State University is one campus with this policy. East Tennessee State University students, faculty, and staff were questioned via email survey about their perceptions of safety on campus and opinions regarding the current concealed carry policy. No significant relationship was found between respondents’ perceptions of safety and their level of support for the current policy, although political affiliation, affiliation with ETSU, gun ownership, and possession of a concealed carry permit were significantly related to support of concealed carry on campus.

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Commercial concealed weapon detection systems are large and expensive and are not suitable to be used as a portable system. Currently, new methods of concealed weapon detection are being developed to build small and compact systems. One such method is based upon the natural resonances of objects; however, no such system has made it to the market due to the low quality of the signals used in the detection algorithms. In this thesis, a prototype concealed weapon detection system is developed and tested for operation in a cluttered environment. This system utilizes the late-time portion of a radar return to extract the resonance information of an unknown target. After proper signal processing and clutter suppression, the signals are classified to determine if the object is a threat. Multiple measurements with frequency-sweep and time-domain systems are used to verify the algorithm. Microwave tissue imaging techniques aim to reconstruct the internal dielectric distribution of the tissue and rely on the dielectric contrast between healthy and malignant tissues. This contrast has been shown to be weak, and therefore, the signals are easily susceptible to noise. This thesis proposes and validates a method for signal-to-noise ratio analysis of complex S-parameter data sets that are used for microwave imaging. A study of de-noising and artifact reduction techniques for microwave holographic imaging is also presented. / Thesis / Master of Applied Science (MASc)

This research was intended to investigate the perceptions of firearm policies and the views held by campus security personnel regarding student or teacher carry on campus. The purpose of the interviews was to investigate campus security officer’s perceptions and how they differ based upon individual belief systems. The goal, therefore, was to understand how their perspectives on campus carry could impact interactions with students and faculty. Exploring a representative sample of current firearm policies, both on and off campus, established a framework that exposed the opinions of campus security personnel and gave some insight into the potential impact that might occur from implementing various policies. As a result, the coverage of these materials was pivotal regarding firearm policy and to show how unique perspectives can develop and create a better understanding of campus policing. This was especially true given the dearth of research into violence on campuses and the perspective of individuals that are tasked with the protection of the institutes.

No description available.