Showing papers by "Manchester Metropolitan University published in 1995"

Agent theories, architectures, and languages: a survey

Abstract: The concept of an agent has become important in both Artificial Intelligence (AI) and mainstream computer science. In this article, we present a survey of what we perceive to be the most important theoretical and practical issues associated with the design and construction of intelligent agents. The article also includes a short review of current and potential applications of agent technology, and closes with a glossary of key terms, an annotated list of systems, and a detailed bibliography. Pointers to further reading are provided throughout.

Testing the Generality of Bird‐Habitat Models

Abstract: Bird-habitat models are frequently used as predictive modeling tools—for example, to predict how a species will respond to habitat modifications. We investigated the generality of the predictions from this type of model. Multivariate models were developed for Golden Eagle (Aquila chrysaetos), Raven (Corvus corax), and Buzzard (Buteo buteo) living in northwest Scotland. Data were obtained for all habitat and nest locations within an area of 2349 km2. This assemblage of species is relatively static with respect to both occupancy and spatial positioning. The area was split into five geographic subregions: two on the mainland and three on the adjacent Island of Mull, which has one of United Kingdom’s richest raptor fauna assemblages. Because data were collected for all nest locations and habitats, it was possible to build models that did not incorporate sampling error. A range of predictive models was developed using discriminant analysis and logistic regression. The models differed with respect to the geographical origin of the data used for model development. The predictive success of these models was then assessed by applying them to validation data. The models showed a wide range of predictive success, ranging from only 6% of nest sites correctly predicted to 100% correctly predicted. Model validation techniques were used to ensure that the models’ predictions were not statistical artefacts. The variability in prediction success seemed to result from methodological and ecological processes, including the data recording scheme and interregional differences in nesting habitat. The results from this study suggest that conservation biologists must be very careful about making predictions from such studies because we may be working with systems that are inherently unpredictable. Los modelos de habitat para aves han sido usados frecuentemente como herramientas predictivas de modelaje, por ejemplo, para predecir como una especie va a responder a modificaciones en el habitat. En el presente estudio investigamos la generalidad de las predicciones hechas por este tipo de modelos. Modelos multivariados fueron desarrollados para las aguilas dorados (Aquila chrysaetos), los cuervos (Corvus corax) y los buitres (Buteo buteo) que habitan el noroeste de Escocia. Se obtuvieron datos para todos los habitat y sitios con nidos dentro de un area de 2349 km2. Este conjunto de especies es relativamente estatico con respectio a su posesion y posicion espacial. El area fue dividida en cinco subregiones geograficas; dos en tierra firme y tres en las islas adyacentes de Mull que poseen una de las asociaciones de fauna de aves de rapina mas ricas del Reino Unido. Debido a que se recolectaron datos de todos los sitios con nidos y habitats, fue posible construir modelos que no incorporaron errores de muestreo. Se desarrollo una serie de modelos predictivos usando analisis discriminante y regresiones logisticas. Los modelos difirieron en lo que respecta al origen geografico de los datos usados en el desarrollo del modelo. El exito predictivo de estos modelos fue evaluado aplicandolos a datos de validacion. Los modelos variaron ampliamente en su exito predictivo, con una prediccion correcta de los sitios con nidos que vario entre un 6% y un 100%. Se utilizaron tecnicas de validacion de modelos que aseguraron que las predicciones de los modelos no eran artificios estadisticos. La variabilidad en el exito predictivo parecio ser el resultado de procesos metodologicos y ecologicos que incluyeron el esquema de registro de los datos y diferencias interregionales en los habitats de anidacion. Los resultados de este estudio sugieren que los biologos de conservacion tienen que ser muy cuidadosos la al hacer predicciones a partir de tales estudios porque se podria estar trabajando con sistemas que son inherentemente impredecibles.

Experimental and numerical assessment of the shallow water model for two-dimensional dam-break type problems

Abstract: Experimental and numerical results concerning the flow induced by the break of a dam on a dry bed are presented. The numerical technique consists of a shock-capturing method of the Godunov type. A physical laboratory model has been employed to infer properties and validity of the numerical solution. Attention is also given to the applicability of the mathematical model, based on the shallow water equations, to this class of problems.

The role of management consultants in the development of information technology: the indissoluble nature of socio‐political and technical skills*

Abstract: This paper explores the role of management consultants in the development of information technology (IT) in organizations Contending that the process of IT systems development is characterized by the exercise of power, the central theme of the argument concerns the indissoluble nature of the technical and socio-political skills inherent in IT consultancy practice IT consultancy practice is not just socio-political when winning a contract - the sales pitch - and technical when developing an IT system Rather, socio-political skills centred on the mobilization of discursive and symbolic resources are an inherent part of the construction of such systems

Applying agent technology

Abstract: The term \" agent \" , (and hence \" agent based computing \" , \" agent based system \" , ''multi-agent system''), is being increasingly used within information technology to describe a broad range of computational entities. These entities range from relatively simple systems, (such as Microsoft's TIP WIZARD, which provides advice to users working in EXCEL 5, or desktop agents which prioritise and filter electronic mail (Maes, 1994)), right up to very large, interoperable expert systems or databases which contain thousands of lines of code (e.g., ARCHON (Jennings et al., 1995) and Carnot (Huhns et al., 1992)). Broadly speaking, we can identify three different classes of agent. At the simplest level, there are \" gopher \" agents, which can execute straightforward tasks based on pre-specified rules and assumptions (e.g., remind me that I have a lecture every Monday this term at 2:00). The next level of sophistication involves \" service performing \" agents, which execute a well-defined high-level task at the request of a user (e.g., arrange a meeting or find an appropriate flight). Finally, there are \" predictive/proactive \" agents, which volunteer information or services to a user, without being

Understanding the Emergence of Conventions in Multi-Agent Systems

Abstract: In this paper, we investigate techniques via which a group of autonomous agents can reach a global agreement on the use of social conventions by using only locally available information. Such conventions play a central role in naturallyoccurring social systems, and there are good masons tbr supposing that they will play a similarly important role in artificial social systems. Following a short review of conventions and their use in distributed artificial intelligence, we present a formal model that rigorously defines both our experimental methodology, and the performance measures we use [o quantify the success of our experiments. We then describe sixteen different mechanisms for bringing about agreement on conventions, and present experimental results obtained for each of these methods. A tentative analysis of these results is given, and the paper concludes with some comments and issues for future work.

The balanced score‐card: short‐term guest or long‐term resident?

Abstract: One recently developed performance measurement method which may prove more effective for hotel management is that of the “balanced score‐card” – which aims to give management a “comprehensive but quick” view of their organization′s performance. Investigates whether the “score‐card” may represent a long‐term solution to the “superior performance measurement method” the hotel sector is apparently looking for – or whether it is more likely to be just a short‐term, passing fad?

Representing and executing agent-based systems

Abstract: In this paper we describe an approach to the representation and implementation of agent-based systems where the behaviour of an individual agent is represented by a set of logical rules in a particular form. This not only provides a logical specification of the agent, but also allows us to directly execute the rules in order to implement the agent's behaviour. Agents communicate with each other through a simple, and logically well-founded, broadcast communication mechanism. In addition, agents can be grouped together. This not only restricts the extent of broadcast messages, but also provides a structuring mechanism within the agent space.

A simple in vitro model for growth control of bacterial biofilms

Abstract: The perfused biofilm fermenter was found to be unsuitable for the long-term culture and growth rate control of Staphylococcus aureus and Pseudomonas aeruginosa biofilms. In a simplified approach, biofilms of these organisms were grown within Sorbarod filter plugs which were perfused with culture medium. Pseudo-steady states were established which were stable over several days at which the growth rate of the biofilm was reproducible, measurable and significantly slower than in broth culture. Environmental scanning electron microscopy of dissected Sorbarods demonstrated an association of cells with the surfaces of individual cellulose fibres, and growth characteristic of biofilms. Relatively high cell numbers recovered from the Sorbarod model facilitated biochemical investigations of biofilm populations and cells released spontaneously from them. SDS-PAGE demonstrated significant differences between the protein profiles of biofilm and eluted populations, which include, in Staph. aureus, the repression of a 48 kDa protein and increased expression of a 21 kDa protein relative to planktonic controls cultured at equivalent growth rates. The paper demonstrates the suitability of the approach for the culture of biofilm samples which are suitable for biochemical analysis.

Customers as oral participants in a service setting

Abstract: Observable oral participation (OOP) of customers, in the service delivery system in general and in a store format retail setting in particular, occurs in many forms and frequencies. Focusses on customer‐to‐customer observable oral participation (OOP2), studied in relation to the more frequently researched customer‐employee observable oral participation (OOP1). From a study of the literature, and through a controlled customer survey at a retail store, findings clearly demonstrate customer reliance on person‐to‐person encounters, even in a predominantly self‐service environment, and identify the characteristics of customers more likely to engage in OOP2. Service providers devote little attention to OOP2 (compared to OOP1) in service delivery. However, OOP2 is a form of word‐of‐mouth which can be observed and, therefore, measured and managed, and customers are arguably a neglected human resource for a service organization. With this in mind, discusses implications for service encounter and human resource man...

The leadership capacity of the European Commission

Abstract: This article focuses on the leadership capacity of the European Commission. Two broad categories of factors are seen as shaping this leadership capacity: the resources of the Commission and the operating contexts of the Commission. The bulk of the article consists of an examination of these categories and of the linkages and interactions between them. A central theme is that there has been, over time, a general increase in the Commission's leadership capacity.

Development of a questionnaire to measure patients' satisfaction with general practitioners' services.

Abstract: BACKGROUND. It is now a requirement that patients' satisfaction with the services obtained from their general practitioner should be surveyed. AIM. The aim of the study was to produce a reliable and valid multidimensional patient satisfaction questionnaire that could be used in general practice. METHOD. Items were originally derived from patients' responses to open-ended questions. The resulting 148-item Likert-scale questionnaire was completed by 1193 patients. General satisfaction items were removed from the set, and responses to remaining items underwent factor analysis. Subscales were produced from items representing each factor. Reliability and validity of each subscale were examined. RESULTS. Five subscales with a total of 40 items resulted from the factor analysis: doctors, access, nurses, appointments and facilities. Each subscale was internally reliable (Cronbach's alpha coefficient between 0.73 and 0.95), and initial tests of validity suggested that all subscales were valid. CONCLUSION. The study has resulted in a 40-item scale that has been found to be reliable and valid after initial tests. Further work to test the reliability and validity of the final version of the patient satisfaction questionnaire is described.

MetateM: An introduction

Abstract: In this paper a methodology for the use of temporal logic as an executable imperative language is introduced. The approach, which provides a concrete framework, calledMetateM, for executing temporal formulae, is motivated and illustrated through examples. In addition, this introduction provides references to further, more detailed, work relating to theMetateM approach to executable logics.

Factors that characterize street injectors

Abstract: Injecting drugs in the streets and other public places is increasingly common in many cities and large towns in the United Kingdom. It is a practice rarely open to view, but the evidence is there in the used needles and syringes left in stairwells of flats, shop doorways, public toilets and other areas where exposure can be avoided. Although it is a development with serious implications for public health, it has received little research attention. This paper reports the factors associated with street injecting from 56 polydrug users who regularly injected in public places. It reveals that they were more likely to be severely drug dependent with associated health problems. A high proportion were homeless. Their drug-related and sexual risk behaviour have implications for the acquisition and transmission of disease.

Estimating propulsive forces in swimming from three‐dimensional kinematic data

Abstract: Propulsive forces are important determinants of swimming performance. The aim of this study was to quantify the measurement error (uncertainty) in propulsive forces calculated from kinematic data. Ten operators digitized underwater video recordings of a breaststroke swimmer's right arm action. Four landmarks on the hand were digitized at 50 Hz and their three‐dimensional coordinates obtained using a DLT algorithm. Two angles (α and ψ) defining the orientation of the hand relative to the fluid flow were calculated following the procedures of Schleihauf et al. (1983). The hydrodynamic force acting on the hand (F R) was calculated using the force coefficients of Schleihauf (1979). Errors in single measurements of hand speed, α and ψ were estimated for each video field analysed. Errors in α and ψ led to average errors in the lift and drag coefficients of 27 and 20% respectively, which, when combined with an average hand speed error of 6%, produced an average error in F R of 26%. Each of these errors was reduc...

Population sizes, status and habitat associations of the restricted-range bird species of Sumba, Indonesia

Abstract: The island of Sumba was visited in 1989 and 1992 with the aim of collecting data on its avifauna. The endemic and other restricted-range bird species are very poorly known and, potentially, at great risk from extinction due to habitat change. Using standardized methods, habitat and bird census data were collected in eight forest areas. Analysis of the habitat data shows that most of the restricted-range species are forest-dependent. The exception is Turnix everetti (Sumba Buttonquail), which is found in open grassland. Discriminant Function Analysis was used to define habitat associations in a more precise and objective way. The species with the most specific requirements are Ptilinopus dohertyi (Red-naped Fruit-dove) and Zoothera dohertyi (Chestnut-backed Thrush), which are associated with primary forest at high altitudes, and Cacatua sulphurea (Sulphur-crested Cockatoo) and Rhyticeros everetti (Sumba Hornbill), which prefer evergreen primary or mature secondary forest at low altitudes. The results of the bird censuses were combined with data on habitat cover from satellite photographs to produce estimates of total population sizes. Among the rarest and most endangered species on Sumba are three which are represented by endemic subspecies: C. sulphurea (estimated population 3,200 birds), Eclectus roratus (Eclectus Parrot) (1,900), Tanygnathus megalorynchos (Great-billed Parrot) (1,700). The rarest endemic species is R. everetti, with a population of approximately 6,500. It is suggested that the census method used – point counts With distance estimates to bird contacts – is the best compromise for multi-species surveys in tropical forests.

How young people make career decisions

Abstract: Although career decision making by young people is of central importance in current training policy in Britain, there has been little recent research into how career decisions are made. Summarizes some of the findings from one such study, in the context of one of the training credits pilot schemes. Based on these findings, describes a complex process of pragmatically rational decision making by young people. This is at odds with the technically rational assumptions that underpin much current education and training policy. Shows assumptions that good quality guidance and better information can help most young people to make “correct” career decisions when they leave school to be fallacious. Suggests that policies need to recognize that changes of mind and of career direction are normal for many young people. We need to work out ways of dealing with this reality, rather than trying to avoid it.

A case for spatial decision‐support systems in retail location planning

Abstract: Despite some significant success stories, there has been only a slow diffusion of awareness of the benefits and application of site evaluation techniques in general, and the application of geographical information systems (GISs) in particular. Four types of factors that have hindered the development of the use of GISs as spatial decision support systems (SDSSs) are outlined: the balance between costs and benefits; the historical development of location and locational marketing strategy within retail businesses; establishment of the role of GISs as SDSSs; and an appreciation of the competitive advantage to be gained by appropriate use of GISs. Argues the latest generation of GISs boasts a number of features that are likely to make them more user friendly and easier to integrate into the total information systems environment within an organization. However, effective use of GISs as SDSSs also depends on full integration of GISs into the armoury of decision‐support tools used by retail managers.

The Civil Service: continuity and change

Abstract: The White paper The Civil Service: Continuity and Change (Cm 2627) (Cabinet Office 1994) was published in July 1994. It was the latest in a series of major policy documents in recent years, the most recent instalment of what has been called Whitehall’s management revolution. As Sir Robin Butler has said (1993, p398), this management revolution did not ’spring on to the stage, fully formed, in 1976, 1979 or on any other date.’ Rather there has been a process of gradual and accelerating change in the shape of each new initiative. These initiatives have been well chronicled and widely analysed (Metcalf and Richards 1990; Massey 1993; Pollitt 1993; Greer 1994; O’Toole and Jordan (eds) 1995). They include the setting up of executive agencies and the separation of policy from operations; competition between different suppliers; the greater use of internal ,

Chalk and cheese: BPR and ethnomethodologically informed ethnography in CSCW

Abstract: Recently a number of methodological approaches have been presented as proffering radical solutions to organisational change This paper discusses one such approach, Business Process Re-engineering (BPR) and contrasts it with Ethnography, a method that has gained some prominence in CSCW The paper suggests, using a number of empirical examples, that despite some superficial similarities, the two approaches differ markedly in their analytical purchase In particular, ethnography's emphasis on understanding 'systems' within the situated context of the work setting rather than as an abstract model of process, has consequences for the successful identification and implementation of system re-design

An Empirical Examination of Factual Information Content among Service Advertisements

Abstract: Services are generally thought to be less tangible to consumers than physical goods, a trait which may create communication diffculties for sellers of service products. To accommodate the special nature of service products and the generally greaterper ceived risk associated with them, many scholars argue that services marketers need to stress factual information in their adver tisements. While this perspective has been advanced for years, little empirical research has been conducted to examine its adoption by practitioners. In this article we investigate the extent to which the advertisers of services emphasise specifically suggested factual information cues in their messages. Over 17,000 newspaper ads and 9,800 television ads were scrutinized to reveal that services advertisements do indeed provide various proposed factual cues and that their incidence increases as ser vice products become more intangible in nature.