At signalized intersections, pedestrians are considered to be amongst the most vulnerable. When in the crosswalk at intersections without protected left-turn phasing, pedestrians are particularly at risk from left-turning vehicles. Until recently, a wide variety of indications were in use across the US to indicate a permissive left-turn condition to the driver. In Oregon, the Flashing Yellow Arrow (FYA) has been used to indicate the permissive left-turn condition for approximately 10 years. With the addition of the FYA in the 2009 MUTCD, it is likely that its use will continue to increase nationally. Though many operational and safety issues have been studied about the FYA indication, this research proposes to fully investigate factors that influence driver behavior in the context of the permissive left-turn conflict with pedestrians. Specifically, the research seeks to study driver glance behavior to identify reasons why drivers are, "looking at but not seeing" pedestrians in or near the crosswalk or not searching for the presence of pedestrians at all. / Graduation date: 2013

We consider the optimization problem of safety stock placement in a supply chain, as formulated in [1]. We prove that this problem is NP-Hard for supply chains modeled as general acyclic networks. Thus, we do not expect to find a polynomial-time algorithm for safety stock placement for a general-network supply chain. / Singapore-MIT Alliance (SMA)

Thesis (MBA)--North-West University, Potchefstroom Campus, 2008.

Medication safety is a key contribution to patient safety in health care settings. Health care researchers and scholars frequently report and discuss nurses medication administration practices or medication errors associated with patients safety in hospitals. Yet there are gaps in published reports about how practitioners view the larger phenomenon of medication safety as it unfolds on a hospital unit. Research is needed to advance our understanding of medication safety as it comes together amidst the interrelated elements in a complex hospital environment, and what practitioners identify and associate with medication safety in this context. In this study, medication safety was explored with participants from nursing and pharmacy departments on one Canadian hospital unit. Using a restorative theoretical approach and citizen science methodology, the researcher engaged in critical conversations with practitioner and decision-maker participants (n=68) to explore elements that support and those that present barriers to medication safety through focus groups, photo walkabouts, on-unit observations, and photo elicitation. Themes from the data revealed that (1) unit structures shape medication safety, (2) medication system design affects medication safety, (3) practitioners embed accountability for medication safety into their practice and processes, (4) unit culture influences medication safety, (5) practitioners devise and employ workarounds to circumvent ongoing barriers to medication safety, and (6) participants envisioned, and in some cases implemented, restorations to improve medication safety on their unit. Findings highlight a range of contextual, interrelated supports for and barriers to medication safety that participants discovered and shared knowledge about on their unit. Participants envisioned medication safety improvements that could be implemented at present and in the future. Workarounds, power, and possibilities for medication safety improvements related to current medication system design in health care systems are discussed.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 111-119).

Thesis (Ph. D.)--University of Rhode Island, 2005. / Typescript. Includes bibliographical references (leaves 143-146).

An increasing emphasis on chemical process safety over the last two decades has led to the development and application of powerful risk assessment tools. Hazard analysis and risk evaluation techniques have developed to the point where quantitatively meaningful risks can be calculated for processes and plants. However, the results are typically presented in semi-quantitative “ranked list” or “categorical matrix” formats, which are certainly useful but not optimal for making business decisions. A relatively new technique for performing valuation under uncertainty, Value at Risk (VaR), has been developed in the financial world. VaR is a method of evaluating the probability of a gain or loss by a complex venture, by examining the stochastic behavior of its components. We believe that combining quantitative risk assessment techniques with VaR concepts will bridge the gap between engineers and scientists who determine process risk and business leaders and policy makers who evaluate, manage, or regulate risk. We present a few basic examples of the application of VaR to hazard analysis in the chemical process industry. We discover that by using the VaR tool we are able to present data that allows management to make better informed decisions.

In this thesis an incident prediction model is formulated and calibrated. The primary idea of the model developed is to correlate the expected number of crashes on any section of a freeway to a set of traffic stream characteristics, so that a reliable estimation of likelihood of crashes can be provided on a real-time basis. Traffic stream variables used as explanatory variables in this model are termed as “incident precursors”. The most promising incident precursors for the model formulation for this research were determined by reviewing past research. The statistical model employed is the categorical log-linear model with coefficient of speed variation and occupancy as the precursors. Peak-hour indicators and roadway-type indicators were additional categorical variables used in the model. The model was calibrated using historical loop detector data and crash reports, both of which were available from test beds in Austin, Texas. An examination of the calibrated model indicated that the model distinguished different levels of crash rate for different precursor values and hence could be a useful tool in estimating the likelihood of incidents for real-time freeway incident management systems.

Management decisions in complex industrial facilities usually consider both the economic and environmental aspects of the plant's performance. For nuclear power plants (NPPs), safety is also a very substantial issue. The objectives of this dissertation are to develop and demonstrate a novel useful conceptual model that could be used to allocate maintenance funds for a nuclear power plant in such a way as to meet all specified safety requirements and objectives, while achieving a high degree of economic performance. The model is based on the general theory that the reliability of a plant at any time is a function of its initial reliability and the maintenance history of the individual plant components (Smith, 1997). Such a model can assist in evaluating strategic management decisions regarding allocation of funds for nuclear power plant maintenance. It could be used as a simulation tool; various scenarios could be studied to answer "what if" questions. Simulations of this type will allow a better understanding of the relationship between maintenance, economic performance, and safety, and consequently will lead to better decision making. The novelty of this model is tied to the intimate relationship that it develops between maintenance activities at a nuclear plant, and their relationship to prescribed safety requirements and to the economic performance of that plant.

Protecting modern engineered systems has become increasingly difficult due to their complexity and the difficulty of predicting potential failures. With the added threat of terrorism, the desire to design systems resilient to potential faults has increased. The concept of a resilient system – one that can withstand unanticipated failures without disastrous consequences – provides promise for designing safer systems. Resilience has been recognized in research settings as a desired end product of specific systems, but resilience as a general, inherent, measurable property of systems had yet to be established. To achieve this goal, system resilience was related to an established concept, the resiliency of a material. System resilience was defined as the amount of energy a system can store before reaching a point of instability. The energy input into each system as well as the system’s exergy were used to develop system stress and system strain variables. Process variable changes to four test systems – a steam pipe, a water pipe, a water pump, and a heat exchanger – were applied to obtain series of system stress and system strain data that were then graphed to form characteristic system response curves. Resilience was quantified by performing power-law regression on each curve to determine the variable ranges where the regression line accurately described the data and where the data began to deviate from that power-law trend. Finally, the four test systems were analyzed in depth by combining them into an overall system using the process simulator ASPEN. The ranges predicted by the overall system data were compared to the ranges predicted for the individual equipment. Finally, future work opportunities were outlined to show potential areas for expansion of the methodology.