Software component testing : a standard and the effectiveness of techniques

This portfolio comprises two projects linked by the theme of software component testing, which is also often referred to as module or unit testing. One project covers its standardisation, while the other considers the analysis and evaluation of the application of selected testing techniques to an existing avionics system. The evaluation is based on empirical data obtained from fault reports relating to the avionics system. The standardisation project is based on the development of the BC BSI Software Component Testing Standard and the BCS/BSI Glossary of terms used in software testing, which are both included in the portfolio. The papers included for this project consider both those issues concerned with the adopted development process and the resolution of technical matters concerning the definition of the testing techniques and their associated measures. The test effectiveness project documents a retrospective analysis of an operational avionics system to determine the relative effectiveness of several software component testing techniques. The methodology differs from that used in other test effectiveness experiments in that it considers every possible set of inputs that are required to satisfy a testing technique rather than arbitrarily chosen values from within this set. The three papers present the experimental methodology used, intermediate results from a failure analysis of the studied system, and the test effectiveness results for ten testing techniques, definitions for which were taken from the BCS BSI Software Component Testing Standard. The creation of the two standards has filled a gap in both the national and international software testing standards arenas. Their production required an in-depth knowledge of software component testing techniques, the identification and use of a development process, and the negotiation of the standardisation process at a national level. The knowledge gained during this process has been disseminated by the author in the papers included as part of this portfolio. The investigation of test effectiveness has introduced a new methodology for determining the test effectiveness of software component testing techniques by means of a retrospective analysis and so provided a new set of data that can be added to the body of empirical data on software component testing effectiveness

The Canadian Overnight Market: Recent Evolution and Structural Changes

Since 1997 when the Bank of Canada last published a review of the Canadian overnight market, several important changes have affected the market's structure and dynamics. Reid provides a current overview of the market, examining the financial instruments, market transparency and flows, and the collateralized overnight rate as it has evolved since the introduction of the Large Value Transfer System and the fixed announcement dates. Other significant influences include changes in market practices regarding risk management, the rise of securities lending, the increased demand for collateral, and the Bank of Canada's measures to reinforce the target for the overnight rate.

Real Return Bonds, Inflation Expectations, and the Break-Even Inflation Rate

According to the Fisher hypothesis, the gap between Canadian nominal and Real Return Bond yields (or break-even inflation rate) should be a good measure of inflation expectations. The authors find that this measure was higher, on average, and more variable than survey measures of inflation expectations between 1992 and 2003. They examine whether risk premiums and distortions embedded in this interest rate gap can account for these facts. Their results indicate that distortions were likely an important reason for the high level and variation of this measure over much of the 1990s. There is little evidence that the distortions examined were as important between 2000 and 2003, but the high level of the break-even inflation rate in 2004 may be evidence of their return. Given the potential distortions, and the difficulty in identifying them, the authors conclude that it is premature to consider this measure a reliable gauge of monetary policy credibility. In addition, it is not as useful as competing tools for short- and medium-term inflation forecasting.Interest rates; Inflation and prices; Market structure and pricing

Real Return Bonds: Monetary Policy Credibility and Short-Term Inflation Forecasting

The break-even inflation rate (BEIR) is calculated by comparing the yields on conventional and Real Return Bonds. Defined as the average rate of inflation that equates the expected returns on these two bonds, the BEIR has the potential to contain useful information about long-run inflation expectations. Yet the BEIR has been higher, on average, and more variable than survey measures of inflation expectations, which may be explained by the effects of premiums and distortions embedded in the BEIR. Because of the difficulty in accounting for these distortions, the BEIR should not be given a large weight as a measure of long-run inflation expectations at this time. However, as the Real Return Bond market continues to develop, the BEIR should become a more useful indicator of inflation expectations. At present, it demonstrates no clear advantage over survey measures and even past inflation rates in forecasting near-term inflation.

Therapeutic potential of the renin angiotensin system in ischaemic stroke

The renin angiotensin system (RAS) consists of the systemic hormone system, critically involved in regulation and homeostasis of normal physiological functions [i.e. blood pressure (BP), blood volume regulation], and an independent brain RAS, which is involved in the regulation of many functions such as memory, central control of BP and metabolic functions. In general terms, the RAS consists of two opposing axes; the ‘classical axis’ mediated primarily by Angiotensin II (Ang II), and the ‘alternative axis’ mediated mainly by Angiotensin-(1–7) (Ang-(1–7)). An imbalance of these two opposing axes is thought to exist between genders and is thought to contribute to the pathology of cardiovascular conditions such as hypertension, a stroke co-morbidity. Ischaemic stroke pathophysiology has been shown to be influenced by components of the RAS with specific RAS receptor antagonists and agonists improving outcome in experimental models of stroke. Manipulation of the two opposing axes following acute ischaemic stroke may provide an opportunity for protection of the neurovascular unit, particularly in the presence of pre-existing co-morbidities where the balance may be shifted. In the present review we will give an overview of the experimental stroke studies that have investigated pharmacological interventions of the RAS

Occupational Lower Extremity Risk Assessment Modeling

Introduction: Lower extremity (LE) work-related musculoskeletal disorders (WMSDs) are known to occur with cumulative exposure to occupational and personal risks. The objective of this dissertation study was to find if creating a quantifiable risk detection model for the LE was feasible. The primary product of the literature review conducted for this study resulted in focusing the attention of the model development process onto creating the initial model of the LE for assessing knee disorder risk factors. Literature Review: LE occupational disorders affect numerous industries and thousands of people each year by affecting any one of the musculoskeletal systems deemed susceptible by the occupational and personal risk factors involved. Industries known to be affected tend to have labor intensive job descriptions. Some of the numerous industry examples include mining, manufacturing, firefighting, and carpet laying. Types of WMSDs noticed by the literature include bursitis, osteoarthritis, stress fractures, tissue inflammation, and nerve entrapment. In addition to the occupationally related disorders that may develop, occupationally related discomforts were also taken into consideration by this study. Generally, both the disorders and the discomforts can be traced to either a personal or occupational risk factor or both. Personal risk factors noted by the literature include a person\u27s physical fitness and health history (such as past injuries). Meanwhile, occupational risks can be generalized to physical postures, activities, and even joint angles. Prevalence data over a three year interval (2003-2005) has found that LE WMSDs make up on average approximately 7.5% of all the WMSD cases reported to the US Occupational Safety and Health Administration (OSHA). When the literature is refined to the information pertaining to occupational knee disorders, the mean prevalence percentage of the same three year range is about 5%. Mean cost for knee injuries were found to be $18,495 (for the year between 2003 and 2004). Methodology: Developing a risk model for the knee meant using groups of subject matter experts for model development and task hazard analysis. Sample occupational risk data also needed to be gathered for each of a series of tasks so that the model could be validated. These sample data were collected from a sample aircraft assembly plant of a US aerospace manufacturer. Results: Based on the disorder and risk data found in the literature, a knee risk assessment model was developed to utilize observational, questionnaire, and direct measure data collection methods. The final version of this study\u27s knee model has an inventory of 11 risk factors (8 occupational and 3 personal) each with varying degrees of risk exposure thresholds (e.g., high risk, moderate risk, or minimal risk). For the occupational risk assessment portion of the model, the results of task evaluations include both an occupational risk resultant score (risk score) and a task risk level (safe or hazardous). This set of results is also available for a cumulative (whole day) assessment. The personal risk assessment portion only produces a risk resultant score. Validation of the knee risk model reveals statistically (t (34) = 1.512, p = 0.156), that it is functioning as it should and can decide between hazardous and safe tasks. Additionally, the model is also capable of analyzing tasks as a series of cumulative daily events and providing an occupational and personal risk overview for individuals. Conclusion: While the model proved to be functional to the given sample site and hypothetical situations, further studies are needed outside of the aerospace manufacturing environment to continue testing both the model\u27s validity and applicability to other industrial environments. The iterative adjustments generated for the occupational risk portion of the model (to reduce false positives and negatives) will need additional studies that will further evaluate professional human judgment of knee risk against this model\u27s results. Future investigations must also make subject matter experts aware of the minimal risk levels of this knee risk assessment model so that task observational results are equally comparable. Additional studies are moreover needed to assess the intimate nature between variable interactions; especially multiple model defined minimal risks within a single task

Networked Heterogeneous Systems in a ROS-Enabled Cloud Environment

It is important in the development of cloud robotics that the challenges presented by transferring computational loads to networked resources are properly addressed. The challenges include network latency, data integrity, security, and privacy. The objective of the present work is to investigate the issues of latency and data integrity in a representative cloud robotics environment. The present work involves setting up a cloud robotics network in an open-source Robot Operating System (ROS) framework and carrying out investigations on the levels of latency and reduction in data integrity as utilization of the network increases. In this study, a virtual datacenter has been set up to provide the foundation on which to build software systems to provide cloud services. Robot Operating System (ROS) framework has been used to facilitate communication among heterogeneous systems in the network. Three types of robots, including the Parrot AR.Drone2.0, the Kobuki Turtlebot 2, and the LEGO EV3 have been implemented in the system. The system has been tested for baseline connectivity and under low- and high-bandwidth conditions to determine the latency and data integrity of the network connections. Additionally, a heterogeneous system consisting of sensor feedback from the AR.Drone2.0 and motor control of the Turtlebot 2 has been built to examine the connection between the devices themselves. Through this study, it has been demonstrated that under low-bandwidth conditions, the network performs reasonably well in the areas of latency and data integrity. However, for high-bandwidth conditions involving image transmission, the network performance deteriorates considerably, both in terms of latency and data integrity. One possible reason is the wireless router used in the current setup. It is also recommended that, especially under high-bandwidth loads, it is necessary for networked systems to perform some portion of their computations on-board and high-bandwidth wireless connectivity to the cloud is facilitated. Ongoing research and future directions are also outlined