18 resultados para formal-ästhetische Qualitäten
em Aston University Research Archive
Resumo:
Purpose – This paper aims to evaluate critically the conventional binary hierarchical representation of the formal/informal economy dualism which reads informal employment as a residual and marginal sphere that has largely negative consequences for economic development and needs to be deterred. Design/methodology/approach – To contest this depiction, the results of 600 household interviews conducted in Ukraine during 2005/2006 on the extent and nature of their informal employment are reported. Findings – Informal employment is revealed to be an extensively used form of work and, through a richer and more textured understanding of the multiple roles that different forms of informal employment play, a form of work that positively contributes to economic and social development, acting both as an important seedbed for enterprise creation and development and as a primary vehicle through which community self-help is delivered in contemporary Ukraine. Research limitations/implications – This survey reveals that depicting informal employment as a hindrance to development and deterring engagement in this sphere results in state authorities destroying the entrepreneurial endeavour and active citizenship that other public policies are seeking to nurture. The paper concludes by addressing how this public policy paradox might start to be resolved. Originality/value – This paper is one of the first to document the role of informal employment in nurturing enterprise creation and development as well as community exchange.
Resumo:
Hard real-time systems are a class of computer control systems that must react to demands of their environment by providing `correct' and timely responses. Since these systems are increasingly being used in systems with safety implications, it is crucial that they are designed and developed to operate in a correct manner. This thesis is concerned with developing formal techniques that allow the specification, verification and design of hard real-time systems. Formal techniques for hard real-time systems must be capable of capturing the system's functional and performance requirements, and previous work has proposed a number of techniques which range from the mathematically intensive to those with some mathematical content. This thesis develops formal techniques that contain both an informal and a formal component because it is considered that the informality provides ease of understanding and the formality allows precise specification and verification. Specifically, the combination of Petri nets and temporal logic is considered for the specification and verification of hard real-time systems. Approaches that combine Petri nets and temporal logic by allowing a consistent translation between each formalism are examined. Previously, such techniques have been applied to the formal analysis of concurrent systems. This thesis adapts these techniques for use in the modelling, design and formal analysis of hard real-time systems. The techniques are applied to the problem of specifying a controller for a high-speed manufacturing system. It is shown that they can be used to prove liveness and safety properties, including qualitative aspects of system performance. The problem of verifying quantitative real-time properties is addressed by developing a further technique which combines the formalisms of timed Petri nets and real-time temporal logic. A unifying feature of these techniques is the common temporal description of the Petri net. A common problem with Petri net based techniques is the complexity problems associated with generating the reachability graph. This thesis addresses this problem by using concurrency sets to generate a partial reachability graph pertaining to a particular state. These sets also allows each state to be checked for the presence of inconsistencies and hazards. The problem of designing a controller for the high-speed manufacturing system is also considered. The approach adopted mvolves the use of a model-based controller: This type of controller uses the Petri net models developed, thus preservIng the properties already proven of the controller. It. also contains a model of the physical system which is synchronised to the real application to provide timely responses. The various way of forming the synchronization between these processes is considered and the resulting nets are analysed using concurrency sets.
Resumo:
A major application of computers has been to control physical processes in which the computer is embedded within some large physical process and is required to control concurrent physical processes. The main difficulty with these systems is their event-driven characteristics, which complicate their modelling and analysis. Although a number of researchers in the process system community have approached the problems of modelling and analysis of such systems, there is still a lack of standardised software development formalisms for the system (controller) development, particular at early stage of the system design cycle. This research forms part of a larger research programme which is concerned with the development of real-time process-control systems in which software is used to control concurrent physical processes. The general objective of the research in this thesis is to investigate the use of formal techniques in the analysis of such systems at their early stages of development, with a particular bias towards an application to high speed machinery. Specifically, the research aims to generate a standardised software development formalism for real-time process-control systems, particularly for software controller synthesis. In this research, a graphical modelling formalism called Sequential Function Chart (SFC), a variant of Grafcet, is examined. SFC, which is defined in the international standard IEC1131 as a graphical description language, has been used widely in industry and has achieved an acceptable level of maturity and acceptance. A comparative study between SFC and Petri nets is presented in this thesis. To overcome identified inaccuracies in the SFC, a formal definition of the firing rules for SFC is given. To provide a framework in which SFC models can be analysed formally, an extended time-related Petri net model for SFC is proposed and the transformation method is defined. The SFC notation lacks a systematic way of synthesising system models from the real world systems. Thus a standardised approach to the development of real-time process control systems is required such that the system (software) functional requirements can be identified, captured, analysed. A rule-based approach and a method called system behaviour driven method (SBDM) are proposed as a development formalism for real-time process-control systems.
Resumo:
There is an increasing emphasis on the use of software to control safety critical plants for a wide area of applications. The importance of ensuring the correct operation of such potentially hazardous systems points to an emphasis on the verification of the system relative to a suitably secure specification. However, the process of verification is often made more complex by the concurrency and real-time considerations which are inherent in many applications. A response to this is the use of formal methods for the specification and verification of safety critical control systems. These provide a mathematical representation of a system which permits reasoning about its properties. This thesis investigates the use of the formal method Communicating Sequential Processes (CSP) for the verification of a safety critical control application. CSP is a discrete event based process algebra which has a compositional axiomatic semantics that supports verification by formal proof. The application is an industrial case study which concerns the concurrent control of a real-time high speed mechanism. It is seen from the case study that the axiomatic verification method employed is complex. It requires the user to have a relatively comprehensive understanding of the nature of the proof system and the application. By making a series of observations the thesis notes that CSP possesses the scope to support a more procedural approach to verification in the form of testing. This thesis investigates the technique of testing and proposes the method of Ideal Test Sets. By exploiting the underlying structure of the CSP semantic model it is shown that for certain processes and specifications the obligation of verification can be reduced to that of testing the specification over a finite subset of the behaviours of the process.
Resumo:
The present investigation is based on a linguistic analysis of the 'Housing Act 1980' and attempts to examine the role of qualifications in the structuring of the legislative statement. The introductory chapter isolates legislative writing as a "sub-variety “of legal language and provides an overview of the controversies surrounding the way it is written and the problems it poses to its readers. Chapter two emphasizes the limitations of the available work on the description of language-varieties for the analysis of legislative writing and outlines the approach adopted for the present analysis. This chapter also gives some idea of the information-structuring of legislative provisions and establishes qualification as a key element in their textualisation. The next three chapters offer a detailed account of the ten major qualification-types identified in the corpus, concentrating on the surface form they take, the features of legislative statements they textualize and the syntactic positions to which they are generally assigned in the statement of legislative provisions. The emerging hypotheses in these chapters have often been verified through a specialist reaction from a Parliamentary Counsel, largely responsible for the writing of the ‘Housing Act 1980’• The findings suggest useful correlations between a number of qualificational initiators and the various aspects of the legislative statement. They also reveal that many of these qualifications typically occur in those clause-medial syntactic positions which are sparingly used in other specialist discourse, thus creating syntactic discontinuity in the legislative sentence. Such syntactic discontinuities, on the evidence from psycholinguistic experiments reported in chapter six, create special problems in the processing and comprehension of legislative statements. The final chapter converts the main linguistic findings into a series of pedagogical generalizations, offers indications of how this may be applied in EALP situations and concludes with other considerations of possible applications.
Resumo:
This research has two focal points: experiences of stigma and experiences of formal support services among teenage mothers. Twenty teenage mothers were interviewed in depth, ten from a one-to-one support service, and ten from a group based support service. Contributions to knowledge consisted of the following. First, regarding experiences of stigma, this research integrated concepts from the social psychology literature and established the effects of stigma which are experienced by teenage mothers, offering reasons for the same. Additionally, further coping mechanisms in response to being stigmatized were discovered and grouped into two new headings: active and passive coping mechanisms. It is acknowledged that for a minority of participants, stigma does have negative effects, however, the majority experiences no such serious negative effects. Secondly, regarding experiences of support services, this research was able to directly compare one-to-one with group based support for teenage mothers. Knowledge was unearthed as to influential factors in the selection of a mode of support and the functions of each of the modes of support, which were categorised under headings for ease of comparison. It was established that there is indeed a link between these two research foci in that both the one-to-one and group based support services fulfil a stigma management function, in which teenage mothers discuss the phenomenon, share experiences and offer advice to others. However, it was also established that this function is of minor importance compared to the other functions fulfilled by the support services.
Resumo:
The success of the Semantic Web, as the next generation of Web technology, can have profound impact on the environment for formal software development. It allows both the software engineers and machines to understand the content of formal models and supports more effective software design in terms of understanding, sharing and reusing in a distributed manner. To realise the full potential of the Semantic Web in formal software development, effectively creating proper semantic metadata for formal software models and their related software artefacts is crucial. In this paper, a methodology with tool support is proposed to automatically derive ontological metadata from formal software models and semantically describe them.
Resumo:
Using a new pan-Indian data set, we examine the factors that potentially influence joint access to formal and informal credit markets. Our results are consistent with the literature and bring some new factors influencing access to credit to the fore.
Resumo:
Semantic Web Service, one of the most significant research areas within the Semantic Web vision, has attracted increasing attention from both the research community and industry. The Web Service Modelling Ontology (WSMO) has been proposed as an enabling framework for the total/partial automation of the tasks (e.g., discovery, selection, composition, mediation, execution, monitoring, etc.) involved in both intra- and inter-enterprise integration of Web services. To support the standardisation and tool support of WSMO, a formal model of the language is highly desirable. As several variants of WSMO have been proposed by the WSMO community, which are still under development, the syntax and semantics of WSMO should be formally defined to facilitate easy reuse and future development. In this paper, we present a formal Object-Z formal model of WSMO, where different aspects of the language have been precisely defined within one unified framework. This model not only provides a formal unambiguous model which can be used to develop tools and facilitate future development, but as demonstrated in this paper, can be used to identify and eliminate errors present in existing documentation.
Resumo:
Provision of information and behavioural instruction has been demonstrated to improve recovery after surgery. However, patients draw on a range of information sources and it is important to establish which sources patients use and how this influences perceptions and behaviour as they progress along the surgical pathway. In this qualitative, exploratory and longitudinal study, the use of information and instruction were explored from the perspective of people undergoing inguinal hernia repair surgery. Seven participants undergoing inguinal hernia repair surgery were interviewed using semi-structured interviews 2 weeks before surgery and 2 weeks and 4 months post-surgery. Nineteen interviews were conducted in total. Topic guides included sources of knowledge, reasons for help-seeking and opting for surgery and factors influencing return to activity. Data were analysed thematically according to Interpretative Phenomenological Analysis. Participants sought information from a range of sources, focusing on informal information sources before surgery and using information and instruction from health-care professionals post-surgery. This information influenced behaviours including deciding to undergo surgery, use of pain medication and returning to usual activity. Anxiety and help-seeking resulted when unexpected post-surgical events occurred such as extensive bruising. Findings were consistent with psychological and sociological theories. Overall, participants were positive about the information and instruction they received but expressed a desire for more timely information on post-operative adverse events.
Resumo:
Purpose: Diabetes is a leading cause of visual impairment in working age population in the UK. This study looked at the causes of Severe Visual Impairment(SVI) in the patients attending diabetic eye clinic and influence on the rate of SVI, over a 12 year period, after introducing retinal screening programmes in the hospital and the community in 1993 (review in 1992, 1998 & 2004). Methods: Medical records of all the patients attending the diabetic eye clinic over a period of 5months(April to August) in 1992, 1998 and 2004 were reviewed. The data collected for each patient included age, sex, ethnic origin, diabetes (type,duration &treatment), the best corrected visual acuity (present and at time of presentation), type and duration of retinopathy and attendance record to both diabetic clinic and diabetic eye clinic. In this study, SVI is defined as a visual acuity of 6/36 or worse in at least one eye. Results: In 1992, of a total 245 patients, 58patients(23.6%) had SVI {38 (15.5% of total) due to diabetic retinopathy [31(12.6%) maculopathy, 2(0.8%) vitreous haemorrhage and 5(2%) retinal detachment] and 20(8.1%) due to non–diabetic retinopathy causes}. In 1998, of a total 297, 77patients(25.9%) had SVI {33(11.1% of total) due to diabetic retinopathy [19(6.4%) maculopathy, 9(3%) proliferative retinopathy, 8(2.7%) vitreous haemorrhage and 3(1%) retinal detachment]and 44(14.8%)due to non–diabetic retinopathy}. In 2004, of a total 471, 72patients(15.2%) had SVI{46(9.7%of total) due to diabetic retinopathy [37(7.8%) maculopathy, 1(0.2%) proliferative retinopathy, 6(1.8%) vitreous haemorrhage and 2(0.4%) retinal detachment]and 26(5.5%) due to non– diabetic retinopathy causes}. Conclusions: Introduction of formalised annual diabetic review including retinal screening and a community retinal screening programme has reduced the rate of severe visual impairment due to diabetic retinopathy, in patients attending diabetic eye clinic, from 15.5% in1992 to 9.7% in2004. Keywords: diabetic retinopathy