The feasibility of using standard Z notation in the design of complex systems

Formal design methods are becoming increasingly recognised as being useful for specifying complex systems. Incorporating formal methods in the early stages of a design process introduces the possibility of using mathematical techniques, hence improving the effectiveness of a design process. The Z notation has been applied mainly to specifying software, although it has also been used for specifying hardware and general systems. The Z notation fulfils two functions in this thesis. The first function is as a notation for representing specifications of complex systems, and the second function is as a notation for representing implementations of the same complex systems. The suitability of the Z notation for these functions is investigated in three studies. Both the specifications and implementations are represented as unified collections of Schemas that describe the behaviour in response to each set of input conditions. In each of the studies, both the specifications and implementations of the complex system take place at an early stage in a design process. Throughout this thesis non rigorous proof sketches prove that the implementations meet the requirements of the specifications

Attainability and Nonattainability Under Anti-Pollution Laws

The central issue with which this paper deals is the effectiveness of alternative air pollution control standards presently in use in the United States. More specifically, an analysis and comparison of effluent air standards versus ambient air standards will be performed. The question of effectiveness will be in the context of how well the alternative pollution control measures achieve society\u27s expectations as goals when the standards are imposed. Society\u27s views are assumed to be reflected through a regional (state) planner. The analysis is performed through the use of optimal control techniques. Initially the effluent air standards model will be examined. Next, the ambient air standard model will be analyzed. Finally, a summary and conclusion section will be presented. In general the results suggest that there is a possibility that the optimal path may explode or fall toward zero. In some cases, finite amounts of pollution may occur as equilibria. In any case, the imposition of either type of pollution constraint will effectively reduce the level of social pollution and in some cases the pollution will naturally fall to zero under the constraint. It is also suggested that selective antipollution laws will not, in general, aid in attempts to clean the air

Relationships Between Stream Order and Management Priority: a Water Quality Case Study

Seagrass, which once dominated the habitat of Oyster Harbour on the south coast of Western Australia has been replaced by macroalgae because of increased nutrient and sediment discharge from the rural dominated catchment. Total Phosphorus (TP), Total Nitrogen (TN), Suspended Sediment (SS) and Electrical Conductivity (EC) concentrations from a catchment – wide (168 sites), event-driven snapshot, water quality monitoring program conducted from 1994 to 1996, were analysed in relation to stream order and published survey data on riparian zone condition. This analysis was performed to examine relationships between stream order, riparian zone condition and water quality, and implications for the allocation of limited resources for stream fencing, rehabilitation and stock exclusion towards the moderation of nutrient loss for the benefit of the harbour at the catchment exit. Eighty percent of the stream length was in low order streams (stream order 1 and 2) and the remainder in order 3 and above. Riparian zone condition worsened as stream order decreased. Total Phosphorus, and to a lesser degree TN and SS, decreased with increasing stream order, whilst EC increased with increasing stream order. Amongst many factors, one factor influencing the change in water quality is that low order streams exhibit the poorest riparian zone condition and therefore have little capacity to moderate paddock nutrient runoff. The systematic change in EC implies that low order streams are dominated proportionally more by surface runoff than groundwater, and hence represent a greater relative opportunity to moderate surface derived nutrients and sediment. In summary, low order streams in this case study represent the greatest length, have the poorest condition, show the highest nutrient and sediment concentrations, have greater surface runoff, and therefore are priority candidates for the purpose of minimising the downstream impacts of nutrients when limited funds are available

Ion probe measurement of oxygen self-diffusion in Al2O3.

Thesis. 1977. Sc.D.--Massachusetts Institute of Technology. Dept. of Materials Science and Engineering.MICROFICHE COPY AVAILABLE IN ARCHIES AND SCIENCE.Vita.Includes bibliographical references.Sc.D

Distribution and Habitat Use of the Golden Crab Chaceon fenneri off Eastern Florida Based on In Situ Submersible and ROV Observations and Potential for Impacts to Deep Water Coral/Sponge Habitat

This study documents the distribution and habitat preferences of the golden crab, a commercially fished species, in relation to deep-sea coral/sponge ecosystems (DSCEs) at 200-900 m depths off eastern Florida. A total of 386 h of videotapes from 94 submersible and remotely operated vehicle (ROV) dives from 1999 to 2009, covering a total distance of 376 km, were reviewed and characterized for habitat type and presence of crabs. The DSCEs surveyed included Lophelia coral mounds, Miami Terrace, Pourtalès Terrace, and Tortugas Valleys. Video transect data also included environmental surveys of proposed deep-water routes for Liquid Natural Gas (LNG) pipelines, LNG port, and telecommunications fiber-optic cable. A total of 351 golden crabs (Chaceon fenneri) were counted and observed on a wide variety of habitat types, including coral thickets, rock escarpments, rock pavement, boulders, and soft bottom. The mean density of golden crabs was greater on soft bottom than on hard bottom habitat (0.342±0.234 vs 0.190±0.121 crabs /1000 m2); within the hard bottom regions, mean density was greater on rock substrate than coral substrate (0.206±0.120 and 0.040±0.035 crabs /1000 m2). The current golden crab fishery operates off eastern Florida in Allowable Crab Fishing Areas (ACFAs) within the deep-water Coral Habitat Areas of Particular Concern (CHAPCs); however, we have documented at least 8 regions within the CHAPCs where the ACFAs overlap probable DSCE habitat. Resource managers should adjust the boundaries of the ACFAs to protect and preserve vulnerable DSCE habitat while allowing benthic fisheries to operate in areas of soft bottom habitat

An embedded randomised controlled retention trial of personalised text messages compared to non-personalised text messages in an orthopaedic setting [version 1; peer review: 1 approved]

Background: Several studies have investigated whether personalising trial documentation can aid recruitment and retention. We did a ‘study within a trial’ (SWAT) evaluating the effectiveness of a personalised text message compared to a non-personalised text message, on the retention rate in a large orthopaedic trial. Methods: The SWAT was embedded in the Knee Replacement Bandaging Study (KReBS) trial. The primary outcome was the proportion of 12-month questionnaires returned. Secondary outcomes were the proportion of questionnaires completed and time to questionnaire return. Binary data were analysed using logistic regression and time to return using Cox proportional hazards regression. Odds ratios (OR) and hazard ratios (HR) are presented, with associated 95% confidence intervals (CI) and p-values. Results: In total, 1465 participants were included in the SWAT. In the personalised group, 644/723 (89.1%) of participants returned a questionnaire, compared to 654/742 (88.1%) in the non-personalised group. The absolute difference in return rate was 0.9% (95% CI: -2.3% to 4.2%; p=0.57). There was no evidence of a difference between the groups in the likelihood of returning a questionnaire (OR 1.09; 95% CI: 0.79 to 1.51; p=0.61), the likelihood of returning a complete questionnaire (OR 1.11; 95% CI: 0.82 to 1.51; p=0.50) nor in time to return (HR 1.05; 95% CI: 0.94 to 1.17; p=0.40). Conclusion: This SWAT adds to the growing evidence base for whether personalised text messages are effective. Registration: ISRCTN87127065 (20/02/2017); SWAT 35 (01/12/2015

Seeing the way: visual sociology and the distance runner's perspective

Employing visual and autoethnographic data from a two‐year research project on distance runners, this article seeks to examine the activity of seeing in relation to the activity of distance running. One of its methodological aims is to develop the linkage between visual and autoethnographic data in combining an observation‐based narrative and sociological analysis with photographs. This combination aims to convey to the reader not only some of the specific subcultural knowledge and particular ways of seeing, but also something of the runner's embodied feelings and experience of momentum en route. Via the combination of narrative and photographs we seek a more effective way of communicating just how distance runners see and experience their training terrain. The importance of subjecting mundane everyday practices to detailed sociological analysis has been highlighted by many sociologists, including those of an ethnomethodological perspective. Indeed, without the competence of social actors in accomplishing these mundane, routine understandings and practices, it is argued, there would in fact be no social order

Poverty and Service Delivery in Suburban America Framing Paper

In the United States today, contrary to popular belief, living in the suburbs is not synonymous with living the American dream. An unprecedented number of people in the suburbs are living on household incomes of less than $20,000, many on much less. Increasingly, individuals and their families need to rely on services and public benefits to meet their basic needs (Kneebone & Berube, 2013). Over the past 30 years, poverty in the suburbs has grown due to multiple factors, including job decentralization, shifts in the location of affordable and subsidized housing, and the relocation to the suburbs of lower income immigrants and minorities (Covington, Freeman, & Stoll, 2011; Frey, 2011a). The rate of growth in suburban poverty has been particularly high in the past decade, outpacing growth in both urban and rural areas. During the Great Recession (2007-2009), high rates of unemployment and underemployment and the home foreclosure crisis brought the number of people living in poverty in the suburbs to an all-time high. Today, suburban areas are home to about 40 percent of all poor people in the country, an increase from 25 percent in 1980. Furthermore, in the 100 largest metropolitan areas, more people are living in poverty in the suburbs than in urban areas (Frey, 2011b). Suburbs are now facing a range of challenges traditionally associated with cities, such as high rates of unemployment and underemployment, lower educational attainment, food insecurity, and lack of access to health care. The increase in the suburban poverty rate is straining social service providers and local governments at a time when resources are shrinking (Allard & Roth, 2010). The Office of the Assistant Secretary for Planning and Evaluation (ASPE) of the U.S. Department of Health and Human Services (HHS) seeks to better understand poverty and service delivery in suburban America, including how the dynamics of suburban poverty may differ from those in rural and urban communities and whether service models may need to be tailored to meet these differences. To that end, ASPE commissioned this framing paper to review and synthesize existing research, analyze the characteristics and service needs of those living in poverty in the suburbs, and identify information and research needed to more fully understand and guide efforts to address suburban poverty. To prepare this review, we used three types of information sources: existing literature, both published and unpublished; a select number of key informant interviews; and two sources of extant U.S. Census Bureau household survey data: the Annual Social and Economic Supplement to the Current Population Survey (CPS), which provides an annual count of the number of people living below 100 percent of the federal poverty level from 1959 to 2011, and the 2009-2011 American Community Survey (ACS) Weighted 3-Year Restricted-Use Files, a household survey of a nationally representative sample of individuals. These data provide information about all suburbs, including but not limited to, the 100 largest metropolitan areas (see Appendix 1). This paper will serve to frame the discussion during the Poverty and Service Delivery in Suburban America Roundtable, to be convened in 2014. The roundtable will bring together researchers, policy 5 experts, practitioners, and federal staff to discuss the issues raised in this paper and gaps in the research, formulate new research questions, consider the implications of the research for service delivery and public benefits, and assess opportunities for HHS and broader federal engagement