Doctor of Philosophy / Civil Engineering / Sunanda Dissanayake / Rural roads account for 90.3% of the 140,476 total centerline miles of roadways in Kansas. In recent years, rural fatal crashes have accounted for about 66% of all fatal crashes. The Highway Safety Manual (HSM) provides models and methodologies for analyzing the safety of various types of highways. Predictive methods in the HSM were developed based on national trends and data from few states throughout the United States. However, these methodologies are of limited use if they are not calibrated for individual jurisdictions or local conditions. The objective of this study was to analyze the HSM calibration procedures for rural multilane segments and intersections in Kansas. The HSM categorizes rural multilane segments as four-lane divided (4D) and four-lane undivided (4U) segments and rural multilane intersections as three-legged intersections with minor-road stop control (3ST), four-legged intersections with minor-road stop control (4ST), and four-leg signalized intersections (4SG). The number of predicted crashes at each segment was obtained according to the HSM calibration process. Results from calibration of rural segments indicated that the HSM overpredicts fatal and injury crashes by 50% and 65% and underpredicts total crashes by 48% and 64% on rural 4D and 4U segments, respectively. The HSM-given safety performance function (SPF) regression coefficients were then modified to capture variation in crash prediction. The adjusted models for 4D and 4U multilane segments indicated significant improvement in crash prediction for rural Kansas. Furthermore, Kansas-specific safety performance functions (SPF)s were developed following the HSM recommendations. In order to develop Kansas-specific SPF, Negative Binomial regression was applied to obtain the most suitable model. Several additional variables were considered and tested in the new SPFs, followed by model validation on various sets of locations. The Kansas-specific SPFs are capable of more accurately predicting total and fatal and injury crashes on multilane segments compared to the HSM and the modified HSM models. In addition to multilane segments, rural intersections on multilane highways were also calibrated according to the HSM methodology. Using crash modification factors for corresponding variables, SPFs were adjusted to obtain final predicted crash frequency at intersections. Obtained calibration factors indicated that the HSM is capable of predicting crashes at intersections at satisfactory level. Findings of this study can be used for improving safety of rural multilane highways.

Thesis (Masters Diploma (Technology))--Cape Technikon, Cape Town, 1995 / The development of a 200 MeV clinical proton therapy facility at the National Accelerator Centre required an interlock and control system to supervise the delivery of radiation to a patient. The interlock and control system is responsible for ensunng that nobody enters the treatment vault during an irradiation, the extraction of the beamstop devices 'from the beam-line to allow the irradiation of the patient and the insertion of those beam-stop devices when an error condition is detected. Because of its nature, the interlock and control system should be designed so that in the event of an error condition being detected, it should fail to a safe state. This is achieved by modelling the interlock and control system with an appropriate modeling method. This thesis describes a graphical modelling method called Petri-nets, which was used to model the system, and the software developed from the model.

This thesis presents two distinct, but linked, studies. Study 1 contrasted interactive [group] brainstorming against its nominal [individual] counterpart. Previous research has pointed to the productivity advantages of nominal brainstorming in terms of idea production rate [ideation], leading theorists to predict 'the end of interactive brainstorming'. Yet interactive brainstorming has remained the most popular means of ideation within organizations. Central to this research is the thesis that previous studies (a) failed to follow the instructions of the concept originator, Osborn (1953) and (b) used samples and conditions that were not representative of the organizations using brainstorming. Using a total of 10 groups sourced from a UK construction company, participants were asked to brainstorm ideas to improve organizational safety performance. Data produced indicated an equal average number of ideas generated, 30 for interactive, 30.2 for nominal, and an equal number of themes generated, 6.6 for interactive, 6.6 for nominal. Along with ideas and themes, post session group cohesion and process satisfaction levels were measured. Results indicated significantly higher levels of cohesion (t (73.75)=2.35, P<.05) and satisfaction (t (71.07)=4.74, P<.001) for the interactive condition over its nominal counterpart. Implications for research in this area are discussed.Study 2 consisted of two strands of research. The utility of interactive brainstorming, demonstrated in Study 1, highlighted its potential as a means of improving participation in safety. This formed the first area of research. The second area of research concerned the design and analysis of a working model in which Leader Member Exchange (LMX) and safety climate were identified as antecedents, compliance and participation as components and self report near miss/accident involvement as outcomes of safety performance. This model, and the potential utility of brainstorming as a means of improving participation, was tested using a longitudinal methodology. Study participants, sourced from the Refuse Collections division of a UK Local Authority, were asked to complete a questionnaire. LMX was measured using Graen and Uhl-Bien's (1995) LMX-7 scale, safety climate using Glendon and Litherland's (2001) questionnaire whilst measures of compliance and participant were sourced from Neal and Griffin (2006). This produced 101 respondents. Following this, brainstorming sessions were conducted with employees to produce safety improvement ideas. Questionnaires were redistributed seven months later and produced 104 respondents. Results indicated no improvement in participation over the period allocated, however, the measures of antecedents, components and outcomes of safety performance produced a number of significant findings. LMX was found to exhibit a direct relationship with accident involvement, however, analysis revealed the fluctuating mediating roles of compliance and participation in this relationship. Safety climate was found to moderate the relationship between LMX, compliance and participation. Although high levels of safety climate corresponded to higher levels of compliance and participation, LMX was seen to improve compliance and participation only in low climate environments, with this relationship reverse in positive safety climates. This finding is contrary to similar research in this area and the implications for future theory are discussed.

D.Phil. (Engineering Management) / The construction industry has been recognised internationally as one of the most dangerous industries in which to work, with the statistics often explained in terms of the industry’s inherently hazardous nature. In Botswana a total of 281 fatalities were reported to government agencies, mainly recorded in the high-risk sectors over the period of 2000-2004. The purpose of this study was to investigate the role played by key stakeholders in the health and safety (H&S) performance of the Botswana construction industry and to evaluate their level of H&S commitment and implementation. The aim was to determine how clients, designers and contractors can successfully contribute to H&S performance. Five objectives were identified in this research study. The first was to examine the role of key stakeholders in minimising H&S accidents and incidents in the overall H&S performance of the construction industry of Botswana. The second was to establish whether relevant health and safety planning measures contribute to health and safety performance of the construction industry in Botswana. Thirdly, it was to investigate the extent to which the existing legislative framework is relevant to health and safety performance in the construction industry. The fourth was to determine health and safety commitment levels of clients, designers and contractors’ top management in the construction industry of Botswana. The final objective was to design a multi-stakeholder consultative framework that would address H&S from inception to implementation of the construction project. These objectives were achieved through a research design which included a literature review, methods used and procedures developed to administer the questionnaires, data-collection and analysis through various statistical methods. These included descriptive statistics and nonparametric inferential statistics. The results are then presented in statistical format, tables and graphs. While the literature review revealed that construction industry H&S in developed nations is driven by legislation and regulations, the analysis indicated that there is neither statutory obligation nor the desire on the part of designers and the clients to consider H&S...

<p>Retail environments are critical transmission points for <i>Listeria monocytogenes</i> to humans. Past studies have shown <i>L. monocytogenes</i> contamination varies widely across retail environments. <i>L. monocytogenes</i> can transmit among environmental surfaces and subsequently from environment to food via cross-contamination. Modified SSOPs (sanitation standard operating procedures) have been shown to have limited impact on reducing <i>L. monocytogenes</i> prevalence in retail deli environments. Food safety culture and climate, such as beliefs, values, and hygiene behaviors, have been identified as factors impacting food safety performance and microbial outputs. Handwashing and its compliance are among the most prominent personal hygiene aspects subjected to investigation in the past decade, illustrating hygiene behavior as a risk factor and an important consideration to ensure food safety. Additionally, effective management and well-designed infrastructure, such as vertical and lateral communication, employees’ training, accountability, and equipment designed to prevent cross-contamination, have also been described as critical contributors to a sustainable food safety program. However, given such a deadly foodborne pathogen as <i>L. monocytogenes</i>, the correlation between food safety culture and its prevalence remains unknown. We hypothesized that there was a relationship among food safety culture management, infrastructure, and <i>L. monocytogenes</i> prevalence at retail. Our goal is to identify additional risk factors on <i>L. monocytogenes </i>control, develop feasible recommendations, and direct resources to enhance food safety. </p> <p>In the present dissertation, we developed and implemented a predictive risk model, along with employee- and management-implemented SSOPs, in 50 deli establishments across six U.S. states to evaluate and control <i>L. monocytogenes</i> contamination risk and prevalence (Chapter 2). The predictive risk model, based on logistic regression, uses five environmental sites to predict <i>L. monocytogenes</i> prevalence in the entire deli environment. It identified 13 high-risk stores, seven of which were confirmed during subsequent monthly sampling. We found that deep clean intervention reduced <i>L. monocytogenes </i>prevalence on non-food contact surfaces both immediately after the intervention and during follow-up, with marginal significance (α_adj=0.0125). The employee- and management-implemented deep clean can control <i>L. monocytogenes</i> prevalence in retail delis; the predictive risk model, though conservative, will require further validations and can be useful for surveillance purposes. </p> <p>Complementary to the above study, we tackled the <i>L. monocytogenes</i> challenge via food safety culture and climate approach (Chapter 3). Concurrently to the monthly environmental sampling, we distributed food safety culture and climate survey to the 50 stores, with one manager and up to five associates from each establishment, over a 12-month period and overlapped with before, after, and follow-up deep clean. We found that stores with lower <i>L. monocytogenes</i> contamination risk had better food safety culture, including greater sense of commitment to food safety program (p_adj=0.0317) and more complete training (p_adj=0.0117). Deep clean improved managers’ (p_adj=0.0243) and associates’ (p_adj=0.0057) commitment to food safety. This study indicates that food safety culture and climate are crucial component in building a viable, sustainable food safety program. </p> <p>Another survey tool was used to evaluate infrastructure designs, management strategies, and sanitation practices in relation to <i>L. monocytogenes</i> control in retail produce environments (Chapter 4). We distributed the survey to 30 retail produce departments across seven U.S. states. Hand hygiene, minimizing cross-contamination, and maximizing equipment cleanability were the most prominent factors in <i>L. monocytogenes</i> control.</p>

Conventional road safety models rely on historical crash data. Locations with high crash injury statistics are given primary interventions. However, crash data are subject to errors, under-reportings, inaccuracy, and requires years to get updated, as crash events are infrequent and partly random(Gettman, Pu, Sayed and Shelby, 2008), as well as road conditions might change. With the advances in connected vehicle technologies, vehicles can be used as mobile sensors that collects driver behavior information. And if found correlated with the crash data, the driver behavior indices can act as safety surrogate measures. This dissertation focuses first on presenting an algorithm for mapping a vehicle sensing big dataset to a digital road network, in a metropolitan city, using the accompanied GPS trajectories. This is a challenging task since the data collected from the on-board-diagnostic port of the vehicle is sampled at a low ping rate, adding to that the excess of GPS noise in urban canyons, which makes the map matching problem even harder. Next, a spatial correlation study is presented. It investigates the spatial relationship between the driver behavior indices (i.e. speed parameters, hard braking and hard acceleration) and crashes (crash frequencies and crash rates, normalized with traffic volume). Highways and non-highway roads are bucketed separately. The other focus of this dissertation is developing an injury-prediction network screening model, that provide safety ranking of road intersections. Novel explanatory variables are derived from the telematics data, such as intersection traffic maneuvers and traffic conflicts. The non-linearity between the explanatory variables as well as the spatial dependency between road intersection is also tested.

The purpose of this study was to explore Zohar’s Multi-Climate Framework for Occupational Safety to determine the effects of staff nurse perceptions of safety priorities in their organization (safety climate) and their work ownership climate (Magnet Hospital designation) on safety citizenship behaviors viewed as in role or extra role. Safety citizenship behaviors are described as behaviors that go beyond the job description to ensure safety. Participants from a convenience sample of three Magnet designated community hospitals in New England completed three scales (Zohar’s Safety Climate Questionnaire, Essentials of Magnetism II and the Safety Citizenship Role Definitions Scale) representing the study variables via an online survey platform. Multivariate analysis of covariance informed the results. Findings include a positive unadjusted relationship between safety climate and work ownership climate (rs=.492, pF (1, 86) = 8.4, p=.005, N=92), controlling for work ownership climate and hospital. Implications include support for a continued focus on better understanding the importance of a positive nursing work environment, a characteristic shared by Magnet designated hospitals, on the presence of safety citizenship behaviors in the acute care environment. A professional work environment should be considered as an important factor in reducing errors in the acute care setting.

System programming languages such as C and C++ are designed to give the programmer full control over the underlying hardware. However, this freedom comes at the cost of type and memory safety violations which may allow an attacker to compromise applications. In particular, type safety violation, also known as type confusion, is one of the major attack vectors to corrupt modern C++ applications. In the past years, several type confusion detectors have been proposed, but they are severely limited by high performance overhead, low detection coverage, and high false positive rates. To address these issues, we propose HexType and V-Type. First, we propose HexType, a tool that provides low-overhead disjoint metadata structures, compiler optimizations, and handles specific object allocation patterns. Thus, compared to prior work, HexType significantly improves detection coverage and reduces performance overhead. In addition, HexType discovers new type confusion bugs in real world programs such as Qt and Apache Xerces-C++. However, HexType still has considerable overhead from managing the disjoint metadata structure and tracking individual objects, and has false positives from imprecise object tracking, although HexType significantly reduces performance overhead and detection coverage. To address these issues, we propose a further advanced mechanism V-Type, which forcibly changes non-polymorphic types into polymorphic types to make sure all objects maintain type information. By doing this, V-Type removes the burden of tracking object allocation and deallocation and of managing a disjoint metadata structure, which reduces performance overhead and improves detection precision. Another major attack vector is memory safety violations, which attackers can take advantage of by accessing out of bound or deleted memory. For memory safety violation detection, combining a fuzzer with sanitizers is a popular and effective approach. However, we find that heavy metadata structure of current sanitizers hinders fuzzing effectiveness. Thus, we introduce FuZZan to optimize sanitizer metadata structures for fuzzing. Consequently, FuZZan improves fuzzing throughput, and this helps the tester to discover more unique paths given the same amount of time and to find bugs faster. In conclusion, my research aims to eliminate critical and common C/C++ memory and type safety violations through practical programming analysis techniques. For this goal, through these three projects, I contribute to our community to effectively detect type and memory safety violations.

A thesis submitted to the Faculty of Arts in fuIrtlment of the requirements for the degree of DOCTOR OF PHILOSOPHIAE in the Department of Criminal Justice at the UNIVERSITY OF ZULULAND, 1995. / Any tertiary campus is a place composed of unique people requiring atypical law enforcement in comparison to other communities. Conflict between commonweal interests and proprietary responsibility calls for an unbiased discretionary and non-repressive approach to policing (protection) in a calm atmosphere that is conducive to learning for a tranquil environment sought in academia. Law enforcement agencies, including university campus protective systems, share the broad and sometimes vague mandate to enforce the law and keep the peace and order among their respective communities. Although a few studies have been conducted into overseas campus protective systems, no similar research has previously been undertaken in Southern Africa. This scientific research is thus the first of its kind in Southern Africa. The objectives of this study are therefore primarily - • to address the short-coming in knowledge about campus law enforcement in Southern Africa. Consequently, this research is aimed to analyze and define the organization and administration of campus protection at selected Southern Africa universities; • to render a clear account of the role and functions. There of by campus law enforcement personnel by means of breaking down their daily duties and activities, and • to account for the nature and extent of campus crime during the year I January to 31 December 1992. The exploratory, descriptive and comparative research is positivistic in nature. On the other hand the analytical research method followed, explored and examined overseas and limited local literature available. The survey-procedure was followed for the purpose of data collection. Pre-structured and coded questionnaires were adopted as measuring-instrument in order to obtain information regarding aspects of diversity relating to organizational and functional campus protection. Ten arbitrary and selected Southern Africa universities were involved in the investigation. Conclusions and recommendations are vested in statistical information derived from these ten universities. The findings indicate that - • substantial and noteworthy progress has been made among campus protective systems in Southern Africa. New and improved facilities, modern equipment, beneficial budgets and reformed standard of personnel have afforded a position to the betterment of university campus protection. While some campus protective systems have enhanced the quality of their performance, many fail to efficaciously utilize these benefits in reaching their imminent objective; • the organizational and administrative functioning of university campus protection constantly show a typical para-military bureaucratic tendency cast in the same mould of the Max Weber's rationalism theory; • cooperation between higher-learning, campus student personnel and campus protection is a matter of course and augmenting the necessity for a particular framework of a cooperative disciplinary programme in order to prevent apprehensiveness of campus crime; • although no national or institutional obligation exists for reporting campus crime separately, the research indicates that the overwhelming preponderance of campus crime prevailing, is a contravention of university disciplinary regulations and criminal offenses against private and institutional property and persons (students and personnel). All aspects of campus jurisdiction must therefore be addressed by purposeful campus protective programmes.

In order to prevent or mitigate the negative consequences of traffic crashes, automakers are developing active safety systems, which aim to prevent or mitigate collisions.  These systems are expensive to develop and as a result automakers and regulators are motivated to forecast the potential benefits of a proposed safety system before it is widely deployed in the vehicle fleet. The objective of this dissertation was to develop a methodology for predicting fleet-wide benefits for emerging crash avoidance systems as if all vehicles were equipped with a system.  Forward Collision Avoidance Systems (FCAS) were used as an example application of this methodology. The methodology developed for this research includes the following components: 1) identification of the target population, 2) development and validation of a driver model, 3) development of injury risk functions, 4) development of a crash severity reduction model, and 5) computation of fleet-wide benefits.  This dissertation presents a general methodology for each of these components that could be used for any active safety system.  Then a specific model is constructed for FCAS. FCAS could potentially be applicable to 31% of all collisions, 6% of serious injury crashes, and 7% of fatal crashes.  Annually, this accounts for 3.3 million collisions and 18,367 fatal crashes.  We developed a model of driver braking in response to a forward collision warning. Next we used logistic regression to develop injury risk functions that predicted the probability of injury given the crash severity ("V) and occupant characteristics.  Finally, we simulated 2,459 real-world rear-end collisions as if the driver had an FCAS with combinations of warnings, brake assist, and autonomous braking.  We found that between 3.4% and 7.2% of crashes could be prevented and that many more could be mitigated in severity.  These systems reduced the number of injured (MAIS2+) drivers in rear-end collisions between 32% and 55%.  In total, the systems could prevent between $184 and $338 million in economic costs associated with crashes per year. / Ph. D.