Evidence for dissociation between the perceptual and visuomotor systems in humans

When a visual stimulus is continuously moved behind a small stationary window, the window appears displaced in the direction of motion of the stimulus. In this study we showed that the magnitude of this illusion is dependent on (i) whether a perceptual or visuomotor task is used for judging the location of the window, (ii) the directional signature of the stimulus, and (iii) whether or not there is a significant delay between the end of the visual presentation and the initiation of the localization measure. Our stimulus was a drifting sinusoidal grating windowed in space by a stationary, two-dimensional, Gaussian envelope (σ=1 cycle of sinusoid). Localization measures were made following either a short (200 ms) or long (4.2 s) post-stimulus delay. The visuomotor localization error was up to three times greater than the perceptual error for a short delay. However, the visuomotor and perceptual localization measures were similar for a long delay. Our results provide evidence in support of the hypothesis that separate cortical pathways exist for visual perception and visually guided action and that delayed actions rely on stored perceptual information.

Developing intrinsically motivated information systems - a critical systems approach

This paper deals with the problematic of development methodologies for organisational information systems and especially with their application to business systems. Historically, information systems development methodologies tend to fail, because either they take the organisational purposefulness for granted, or they do not analyse it thoroughly. This paper's position is that the analysis, and the definition or redefinition of the systemic purpose are regarded as the utmost expression of the system 's purposefulness. This is to be achieved by ensuring the participation of all the stakeholders who affect, or are affected by, a particular business system's operations. The nature of participation, defined as a process of the stakeholders' perceptual exchanges, is deemed to be problematic in itself, due to the influence exerted upon it by organisational power, coercion and false consciousness. The paper highlights the philosophical reasons for the failures of information systems development methodologies, and provides a conceptual solution to this problematic as well as a strategy for the development of intrinsically motivated organisational information systems. The intrinsically motivated information systems methodology outlined here (BSPA) is intended to yield organisational information systems that demonstrably improve co-ordination of organisational activities, by enabling the development and maintenance of a single/multifaceted view of purpose throughout organisations.

Accounting information systems as knowledge objects:some effects of objectualization

This paper will outline a research methodology informed by theorists who have contributed to actor network theory (ANT). Research informed from such a perspective recognizes the constitutive role of accounting systems in the achievement of broader social goals. Latour, Knoor Cetina and others argue that the bringing in of non-human actants, through the growth of technology and science, has added immeasurably to the complexity of modern society. The paper ‘sees’ accounting and accounting systems as being constituted by technological ‘black boxes’ and seeks to discuss two questions. One concerns the processes which surround the establishment of ‘facts’, i.e. how ‘black boxes’ are created or accepted (even if temporarily) within society. The second concerns the role of existing ‘black boxes’ within society and organizations. Accounting systems not only promote a particular view of the activities of an organization or a subunit, but in their very implementation and operation ‘mobilize’ other organizational members in a particular direction. The implications of such an interpretation are explored in this paper. Firstly through a discussion of some of the theoretic constructs that have been proposed to frame ANT research. Secondly an attempt is made to relate some of these ideas to aspects of the empirics in a qualitative case study. The case site is in the health sector and involves the implementation of a casemix accounting system. Evidence from the case research is used to exemplify aspects of the theoretical constructs.

Information systems management positions - a market perspective

Information systems (IS) managers have become key senior executives for organising the IT resources for delivering support to businesses. Understanding characteristics of IS managers’ employment positions is hence an increasingly important topic in computer personnel research. An investigation in Singapore that included a job advertisement analysis, surveys and case studies was thus conducted to investigate such aspects. This article presents the findings of the job advertisement analysis concerning what kinds of IS managers the market is seeking and what are the basic conditions for such management positions. The literature in this area asserts that job advertisements represent firms’ wishes and the nature of the conditions required of different IS personnel. The results of this analysis therefore reflect a collective market perspective about the changing IS managerial workplace. The results of the analysis benefit both firms and IS employees in formulating personnel development plans and actions, and raise issues for further research.

Information systems design for the community health services

This system is concerned with the design and implementation of a community health information system which fulfils some of the local needs of fourteen nursing and para-medical professions in a district health authority, whilst satisfying the statutory requirements of the NHS Korner steering group for those professions. A national survey of community health computer applications, documented in the form of an applications register, shows the need for such a system. A series of general requirements for an informations systems design methodology are identified, together with specific requirements for this problem situation. A number of existing methodologies are reviewed, but none of these were appropriate for this application. Some existing approaches, tools and techniques are used to define a more suitable methodology. It is unreasonable to rely on one single general methodology for all types of application development. There is a need for pragmatism, adaptation and flexibility. In this research, participation in the development stages by those who will eventually use the system was thought desirable. This was achieved by forming a representative design group. Results would seem to show a highly favourable response from users to this participation which contributed to the overall success of the system implemented. A prototype was developed for the chiropody and school nursing staff groups of Darlington health authority, and evaluations show that a significant number of the problems and objectives of those groups have been successfully addressed; the value of community health information has been increased; and information has been successfully fed back to staff and better utilised.

The evaluation of information systems in the organisational context of the National Health Service. Available in 2 volumes.

This thesis describes a project which has investigated the evaluation of information systems. The work took place in, and is related to, a specific organisational context, that of the National Health Service (NHS). It aims to increase understanding of the evaluation which takes place in the service and the way in which this is affected by the NHS environment. It also investigates the issues which surround some important types of evaluation and their use in this context. The first stage of the project was a postal survey in which respondents were asked to describe the evaluation which took place in their authorities and to give their opinions about it. This was used to give an overview of the practice of IS evaluation in the NHS and to identify its uses and the problems experienced. Three important types of evaluation were then examined in more detail by means of action research studies. One of these dealt with the selection and purchase of a large hospital information system. The study took the form of an evaluation of the procurement process, and examined the methods used and the influence of organisational factors. The other studies are concerned with post-implementation evaluation, and examine the choice of an evaluation approach as well as its application. One was an evaluation of a community health system which had been operational for some time but was of doubtful value, and suffered from a number of problems. The situation was explored by means of a study of the costs and benefits of the system. The remaining study was the initial review of a system which was used in the administration of a Breast Screening Service. The service itself was also newly operational and the relationship between the service and the system was of interest.

Development of performance models for co-operative information systems in an organisational context

The thesis reports of a study into the effect upon organisations of co-operative information systems (CIS) incorporating flexible communications, group support and group working technologies. A review of the literature leads to the development of a model of effect based upon co-operative business tasks. CIS have the potential to change how co-operative business tasks are carried out and their principal effect (or performance) may therefore be evaluated by determining to what extent they are being employed to perform these tasks. A significant feature of CIS use identified is the extent to which they may be designed to fulfil particular tasks, or by contrast, may be applied creatively by users in an emergent fashion to perform tasks. A research instrument is developed using a survey questionnaire to elicit users judgements of the extent to which a CIS is employed to fulfil a range of co-operative tasks. This research instrument is applied to a longitudinal study of Novell GroupWise introduction at Northamptonshire County Council during which qualitative as well as quantitative data were gathered. A method of analysis of questionnaire results using principles from fuzzy mathematics and artificial intelligence is developed and demonstrated. Conclusions from the longitudinal study include the importance of early experiences in setting patterns for use for CIS, the persistence of patterns of use over time and the dominance of designed usage of the technology over emergent use.

Strategic information systems at the Colombian President's Office (1990-1992) : a managerial cybernetic approach

This research studies the issue of using strategic information technology for improving organisational effectiveness. It analyses different academic approaches explaining the nature of information systems and the need organisations feel of developing strategic information systems planning processes, to improve organisational effectiveness. It chooses Managerial Cybernetics as the theoretical foundation supporting development of a "Strategic Information Systems Planning" Framework, and uses it for supporting the analysis of a documented story about the process lived by the Colombian President's Office, in 1990-1992. It argues that by analysing the situation through this new analysis framework we may enlighten some previously unclear situations lived, and not yet properly explained through other approaches to strategic information systems planning. The documented history explains the organisational context and strategic postures of the Colombian President's Office and the Colombian Public Sector, at that time, as well as some of the strategic information systems defined and developed. In particular it analyses a system developed jointly by the President's Office and the National Planning Department, for measuring results of the main national development programmes. Then, it reviews these situations, in the light of the new framework and presents the main findings of the exercise. Finally, it analyses the whole research exercise, the perceived usefulness of the chosen frameworks and tools to enlighten the real situations analysed that were not clear enough, and some open research paths to follow for future researchers interested in the issue.

Designing a methodology for an office communication and information system:for executives in the Malaysian public sector : the Prime Minister's office

Modern managers are under tremendous pressure in attempting to fulfil a profoundly complex managerial task, that of handling information resources. Information management, an intricate process requiring a high measure of human cognition and discernment, involves matching a manager's lack of information processing capacity against his information needs, with voluminous information at his disposal. The nature of the task will undoubtedly become more complex in the case of a large organisation. Management of large-scale organisations is therefore an exceedingly challenging prospect for any manager to be faced with. A system that supports executive information needs will help reduce managerial and informational mismatches. In the context of the Malaysian public sector, the task of overall management lies with the Prime Minister and the Cabinet. The Prime Minister's Office is presently supporting the Prime Minister's information and managerial needs, although not without various shortcomings. The rigid formalised structure predominant of the Malaysian public sector, so opposed to dynamic treatment of problematic issues as faced by that sector, further escalates the managerial and organisational problem of coping with a state of complexity. The principal features of the research are twofold: the development of a methodology for diagnosing the problem organisation' and the design of an office system. The methodological development is done in the context of the Malaysian public sector, and aims at understanding the complexity of its communication and control situation. The outcome is a viable model of the public sector. `Design', on the other hand, is developing a syntax or language for office systems which provides an alternative to current views on office systems. The design is done with reference to, rather than for, the Prime Minister's Office. The desirable outcome will be an office model called Office Communication and Information System (OCIS).

Understanding accountants' participation in accounting information systems implementation : Malaysian evidence

The study is a two-part study starting with a nationwide survey in the private sector. The hypotheses derived from the Western literature were not significantly supported when the results were analyzed. It seems that the existing literature related to the phenomenon under investigation is mainly Anglo-Saxon culture oriented which is different from the Malaysian culture where the study was conducted. However, access barriers to private sector organizations shifted the focus of the research to the second part of the study that examined the issues in detail in four public sector organizations currently implementing accounting information systems – two hospitals and two universities. In the second part of the main study, the researcher developed formal and substantive propositions from the qualitative interviews which were substantiated using a cross-case analysis; as a result, a model for accountants’ participation in AIS implementation is proposed. The research shows that the process of influencing accountants to participate in AIS implementation is more complex than the literature suggests. There were many issues that surfaced during the case studies, such as conflict and empowerment which set a foundation for further research about how participation can be secured to help make the implementation of AIS part of an organizational agenda success.

The Application of Geographic Information Systems to climate change & land evaluation : a study of the effects of climate change upon crop productivity in a sub-tropical environment

This research investigates the contribution that Geographic Information Systems (GIS) can make to the land suitability process used to determine the effects of a climate change scenario. The research is intended to redress the severe under representation of Developing countries within the literature examining the impacts of climatic change upon crop productivity. The methodology adopts some of the Intergovernmental Panel on Climate Change (IPCC) estimates for regional climate variations, based upon General Circulation Model predictions (GCMs) and applies them to a baseline climate for Bangladesh. Utilising the United Nations Food & Agricultural Organisation's Agro-ecological Zones land suitability methodology and crop yield model, the effects of the scenario upon agricultural productivity on 14 crops are determined. A Geographic Information System (IDRISI) is adopted in order to facilitate the methodology, in conjunction with a specially designed spreadsheet, used to determine the yield and suitability rating for each crop. A simple optimisation routine using the GIS is incorporated to provide an indication of the 'maximum theoretical' yield available to the country, should the most calorifically significant crops be cultivated on each land unit both before and after the climate change scenario. This routine will provide an estimate of the theoretical population supporting capacity of the country, both now and in the future, to assist with planning strategies and research. The research evaluates the utility of this alternative GIS based methodology for the land evaluation process and determines the relative changes in crop yields that may result from changes in temperature, photosynthesis and flooding hazard frequency. In summary, the combination of a GIS and a spreadsheet was successful, the yield prediction model indicates that the application of the climate change scenario will have a deleterious effect upon the yields of the study crops. Any yield reductions will have severe implications for agricultural practices. The optimisation routine suggests that the 'theoretical maximum' population supporting capacity is well in excess of current and future population figures. If this agricultural potential could be realised however, it may provide some amelioration from the effects of climate change.

Exchange-traded funds and information asymmetry

This thesis focuses on three main questions. The first uses ExchangeTraded Funds (ETFs) to evaluate estimated adverse selection costs obtained spread decomposition models. The second compares the Probability of Informed Trading (PIN) in Exchange-Traded Funds to control securities. The third examines the intra-day ETF trading patterns. These spread decomposition models evaluated are Glosten and Harris (1988); George, Kaul, and Nimalendran (1991); Lin, Sanger, and Booth (1995); Madhavan, Richardson, and Roomans (1997); Huang and Stoll (1997). Using the characteristics of ETFs it is shown that only the Glosten and Harris (1988) and Madhavan, et al (1997) models provide theoretically consistent results. When the PIN measure is employed ETFs are shown to have greater PINs than control securities. The investigation of the intra-day trading patterns shows that return volatility and trading volume have a U-shaped intra-day pattern. A study of trading systems shows that ETFs on the American Stock Exchange (AMEX) have a U-shaped intra-day pattern of bid-ask spreads, while ETFs on NASDAQ do not. Specifically, ETFs on NASDAQ have higher bid-ask spreads at the market opening, then the lowest bid-ask spread in the middle of the day. At the close of the market, the bid-ask spread of ETFs on NASDAQ slightly elevated when compared to mid-day.

Bandwidth management of WiMAX systems and performance modeling

WiMAX has been introduced as a competitive alternative for metropolitan broadband wireless access technologies. It is connection oriented and it can provide very high data rates, large service coverage, and flexible quality of services (QoS). Due to the large number of connections and flexible QoS supported by WiMAX, the uplink access in WiMAX networks is very challenging since the medium access control (MAC) protocol must efficiently manage the bandwidth and related channel allocations. In this paper, we propose and investigate a cost-effective WiMAX bandwidth management scheme, named the WiMAX partial sharing scheme (WPSS), in order to provide good QoS while achieving better bandwidth utilization and network throughput. The proposed bandwidth management scheme is compared with a simple but inefficient scheme, named the WiMAX complete sharing scheme (WCPS). A maximum entropy (ME) based analytical model (MEAM) is proposed for the performance evaluation of the two bandwidth management schemes. The reason for using MEAM for the performance evaluation is that MEAM can efficiently model a large-scale system in which the number of stations or connections is generally very high, while the traditional simulation and analytical (e.g., Markov models) approaches cannot perform well due to the high computation complexity. We model the bandwidth management scheme as a queuing network model (QNM) that consists of interacting multiclass queues for different service classes. Closed form expressions for the state and blocking probability distributions are derived for those schemes. Simulation results verify the MEAM numerical results and show that WPSS can significantly improve the network's performance compared to WCPS.