Algebraic foundations for qualitative calculi and networks

A qualitative representation $\phi$ is like an ordinary representation of a relation algebra, but instead of requiring $(a; b)^\phi = a^\phi | b^\phi$, as we do for ordinary representations, we only require that $c^\phi\supseteq a^\phi | b^\phi \iff c\geq a ; b$, for each $c$ in the algebra. A constraint network is qualitatively satisfiable if its nodes can be mapped to elements of a qualitative representation, preserving the constraints. If a constraint network is satisfiable then it is clearly qualitatively satisfiable, but the converse can fail. However, for a wide range of relation algebras including the point algebra, the Allen Interval Algebra, RCC8 and many others, a network is satisfiable if and only if it is qualitatively satisfiable. Unlike ordinary composition, the weak composition arising from qualitative representations need not be associative, so we can generalise by considering network satisfaction problems over non-associative algebras. We prove that computationally, qualitative representations have many advantages over ordinary representations: whereas many finite relation algebras have only infinite representations, every finite qualitatively representable algebra has a finite qualitative representation; the representability problem for (the atom structures of) finite non-associative algebras is NP-complete; the network satisfaction problem over a finite qualitatively representable algebra is always in NP; the validity of equations over qualitative representations is co-NP-complete. On the other hand we prove that there is no finite axiomatisation of the class of qualitatively representable algebras.Comment: 22 page

I want it all and I want it now. Challenging the traditional nursing academic paradigm

A recent Twitter chat facilitated by the @NurseEducToday socialmedia team provoked a particularly strong reaction among a range of contributors. The focus of the discussion – expectations of the nurse academic – resulted in a high level of engagement from several participants who clearly held strong views, which were surprisingly polarised. Here we explore aspects of this polarization; and what it might mean for nurses working in academia. Our aim is to reflect on what this dialogue might tell us about current thinking in the profession, specifically around how nurse academics see themselves, what they expect from self and others, and what they are prepared to do to meet these,often, self-generated expectations

Composing features by managing inconsistent requirements

One approach to system development is to decompose the requirements into features and specify the individual features before composing them. A major limitation of deferring feature composition is that inconsistency between the solutions to individual features may not be uncovered early in the development, leading to unwanted feature interactions. Syntactic inconsistencies arising from the way software artefacts are described can be addressed by the use of explicit, shared, domain knowledge. However, behavioural inconsistencies are more challenging: they may occur within the requirements associated with two or more features as well as at the level of individual features. Whilst approaches exist that address behavioural inconsistencies at design time, these are overrestrictive in ruling out all possible conflicts and may weaken the requirements further than is desirable. In this paper, we present a lightweight approach to dealing with behavioural inconsistencies at run-time. Requirement Composition operators are introduced that specify a run-time prioritisation to be used on occurrence of a feature interaction. This prioritisation can be static or dynamic. Dynamic prioritisation favours some requirement according to some run-time criterion, for example, the extent to which it is already generating behaviour

Nurses\u27 use of universal precautions

Research into Acquired Immune Deficiency Syndrome, Hepatitis B., and other bloodborne pathogens has led to the current worldwide awareness that patients can be admitted to hospitals with potentially fatal diseases that can remain undetected in blood and certain body fluids. This has resulted in a change of emphasis in Infection Control, namely isolating the source of infection rather than isolating the diagnosed infectious patient. One such technique recommended to protect healthcare workers, and other patients from nosocomial disease, is Universal Precautions. This study, using a descriptive survey design and structured questionnaire examined nurses\u27 stated compliance to this technique in a suburban, non-teaching hospital of over 100 beds. The 77 subjects, who volunteered to complete a questionnaire, were all currently involved in direct patient care. Nursing staff working in the General Geriatric Ward, Psycho-Geriatric Ward, General Surgical/Medical Ward, Maternity Ward, and Operating Rooms were invited to take part in the study. The data collection took place over a one week period by the investigator personally taking the questionnaires to the wards. The analysis of the data, using a Statistical Analysis System, showed that even though the level of knowledge and opinion level were positive, the stated practice of Universal Precautions was low. The range of correlations was so small that the planned multiple regression was only carried out for one variable, knowledge, the result of which was F( 1. 75)= l.38 P\u3c.24., which was not significant. The results of one-way analysis of variance computed for stated practice by experience, level designation, and area of work were not significant. This study revealed that though nurses may have a reasonable level of knowledge, and a positive opinion towards Universal Precautions, the Stated Practice may be low regardless of the years of experience, level of employment or area of work. Research needs to be continued to further examine what other factors may be influencing the lack of stated compliance by nurses’ to Universal Precautions, a recommended technique of nosocomial disease protection

Concentration

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Examination of the Determinants of Whether Registered Auditing Firms Correct Their Quality Control System Defects Identified in PCAOB Inspection Reports

The Public Company Accounting Oversight Board [PCAOB] is charged with inspecting both individual public company audits as well as audit firm quality control systems. PCAOB inspection reports include information on deficiencies in dividual audits as well as quality control system defects. However, portions of the reports describing any quality control system defects are not made unless the firm does not correct those deficiencies withm one year. 1 classify in inspection public each firm as Type 1, Type 2 or Type 3. Type 1 firms are those whose quality control defects were uncorrected and therefore disclosed after the allotted year, those that had control system defects and corrected those defects system Type 2 firms are within the year. Type 3 firms never had quality control system defects. As the quality control system defects for Type 2 firms are not made public, subtle wording differences in Part B of PCAOB inspection reports allow a reader to distinguish between Type 2 and Type 3 firms as inspection reports for Type 3 firms explicitly state that the inspection team identified no quality control system defects. This study explores the characteristics of audit firms that have quality control system defects and the determinants of whether those firms resolve their quality control system defects within the allotted year. I examine these questions based on data hand-collected from publicly available PCAOB inspection reports. I find that variables indicative of firm size, particularly number of partners, may be positively associated with the tendency to correct quality control system defects in a timely manner. Also, I find that firms with more issuer clients scaled by proxies for firm less likely to correct their quality control system defects. Similarly, I find that firms with only one partner may be less likely to correct their quality control system defects. Finally, my results show that firms who provide written responses size are to PCAOB inspection reports are more likely to fi x their quality control system the allotted year. These findings are important because there has been little research on the inspection reports of triennially-inspected firms (audit firms defects. defects in with 100 or fewer issuer clients), particularly on the quality control system Because PCAOB inspection reports are more opaque than the Peer Review reports they replaced, it is important for users to be aware of potential relationships between firm characteristics and whether or not that firm corrects its quality control system defects. Further, it is important that the PCAOB understand w inspections are likely to prompt improvements in quality

Prior probability information impairs goalkeeper judgments of penalty kick direction [Abstract]

Conference abstract