Research safety vehicle - phase II. Volume I: executive summary. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Mobile parametric measurement device. Volume I: operation. Users manual.

National Highway Traffic Safety Administration, Washington, D.C.

Mobile parametric measurement device. Volume III: data reduction procedures. Users manual.

National Highway Traffic Safety Administration, Washington, D.C.

The Fairchild ESV family sedan - final report. Volume 2.

National Highway Traffic Safety Administration, Washington, D.C.

Input response tests of selected small passenger cars. Final report.

Mode of access: Internet.

Operational hybrid computer simulation for vehicle handling studies. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Research safety vehicle - phase II. Volume IIIb: subcontractor final reports.

National Highway Traffic Safety Administration, Washington, D.C.

The threat of predictable and unpredictable pain: Differential effects on central nervous system processing?

Central nervous system performance is disrupted by pain and by the threat of pain. It is not known whether disruption caused by the threat of pain is dependent on the likelihood of pain occurring. We hypothesised that when a painful stimulus is possible but unpredictable central nervous system performance is reduced, but when the pain is predictable and unavoidable it is not. Sixteen healthy subjects performed a reaction time task during predictable and unpredictable conditions (100% and 50% probability of pain, respectively). Group data showed increased reaction time with the threat of pain by 50 ms (95% Cl 16 to 83 ms) for the predictable condition and 46 ms (95% CI 12 to 80 ms) for the unpredictable condition (p < 0.01 for both), but there was no difference between predictable and unpredictable conditions (p = 0.41). However, individual data showed that there was a differential effect in 75% of subjects (p < 0.05 for all) and that there was a greater effect of predictable pain for some subjects and a greater effect of unpredictable pain for others. Reaction time was related to reported anxiety (r = 0.49, p = 0.02 for both conditions). The predictability of a painful stimulus may have a differential effect on central nervous system performance within individuals, but anxiety about the impending pain appears to be important in determining this effect.

Investigation of the benefits of HIV/AIDS caregiving and relations among caregiving adjustment, benefit finding, and stress and coping variables

The present study explored the nature of benefit finding in HIV/AIDS caregiving, and examined relations among caregiver adjustment, benefit finding, and stress and coping variables. A total of 64 HIV/AIDS caregivers and 46 care recipients completed interviews and questionnaires. First, the study aimed to explore the types of benefits associated with HIV/AIDS caregiving. Content analyses of caregiver responses to an interview question inquiring about gains from caregiving revealed eight benefit themes. Second, the study aimed to examine relations between caregiver adjustment and both benefit finding and stress and coping variables. We hypothesized that number of caregiver reported benefits, social support, challenge and control appraisals, and problem focused coping would be inversely related to poorer adjustment, whereas care recipient reported global distress and illness, caregiver threat appraisal and passive-avoidant emotion-focused coping would be positively associated with poorer adjustment. Correlations indicated that poorer adjustment (measured by global distress, depression, caregiving impact, social adjustment and health status) was positively correlated with care-recipient distress, threat appraisals and passive avoidant coping and inversely correlated with social support, and number of reported benefits. Unexpectedly, problem-focused coping, controllability and challenge appraisals, and care recipient illness were unrelated to adjustment. Third, the study aimed to examine relations between benefit finding and stress and coping variables. Correlations indicated that benefit finding was related to social support use, seeking social support coping and problem-solving coping. Findings indicate that the benefit finding and stress/coping frameworks have utility in guiding research into adaptation to HIV/AIDS caregiving. Results also indicate targets for intervention in the provision of services for HIV/AIDS caregivers.

A case study in specification and implementation testing

Achieving consistency between a specification and its implementation is an important part of software development In previous work, we have presented a method and tool support for testing a formal specification using animation and then verifying an implementation of that specification. The method is based on a testgraph, which provides a partial model of the application under test. The testgraph is used in combination with an animator to generate test sequences for testing the formal specification. The same testgraph is used during testing to execute those same sequences on the implementation and to ensure that the implementation conforms to the specification. So far, the method and its tool support have been applied to software components that can be accessed through an application programmer interface (API). In this paper, we use an industrially-based case study to discuss the problems associated with applying the method to a software system with a graphical user interface (GUI). In particular, the lack of a standardised interface, as well as controllability and observability problems, make it difficult to automate the testing of the implementation. The method can still be applied, but the amount of testing that can be carried on the implementation is limited by the manual effort involved.

A structural method for the design of fault tolerant distributed control systems

Distributed digital control systems provide alternatives to conventional, centralised digital control systems. Typically, a modern distributed control system will comprise a multi-processor or network of processors, a communications network, an associated set of sensors and actuators, and the systems and applications software. This thesis addresses the problem of how to design robust decentralised control systems, such as those used to control event-driven, real-time processes in time-critical environments. Emphasis is placed on studying the dynamical behaviour of a system and identifying ways of partitioning the system so that it may be controlled in a distributed manner. A structural partitioning technique is adopted which makes use of natural physical sub-processes in the system, which are then mapped into the software processes to control the system. However, communications are required between the processes because of the disjoint nature of the distributed (i.e. partitioned) state of the physical system. The structural partitioning technique, and recent developments in the theory of potential controllability and observability of a system, are the basis for the design of controllers. In particular, the method is used to derive a decentralised estimate of the state vector for a continuous-time system. The work is also extended to derive a distributed estimate for a discrete-time system. Emphasis is also given to the role of communications in the distributed control of processes and to the partitioning technique necessary to design distributed and decentralised systems with resilient structures. A method is presented for the systematic identification of necessary communications for distributed control. It is also shwon that the structural partitions can be used directly in the design of software fault tolerant concurrent controllers. In particular, the structural partition can be used to identify the boundary of the conversation which can be used to protect a specific part of the system. In addition, for certain classes of system, the partitions can be used to identify processes which may be dynamically reconfigured in the event of a fault. These methods should be of use in the design of robust distributed systems.

Gas-fired radiant heaters

This dissertation covers four areas of particular interest for the successful application of radiant heating in industrial environments. In it the author tackles the problem of how to predict the thermal comfort produced both by single heaters and also systems of heaters; proposes a method for modelling the mechanisms by which heaters interact with the buildings in which they are installed, in the static and dynamic cases; explores techniques for measuring the radiation produced by heaters; and presents experiments concerned with finding the temperatures and power balances prevailing during normal operation. It is contended that, whilst the generally accepted guides for sizing and operating space heating plant were a good first approximation, there are intrinsic subtleties arising from the fact that the primary mode of heat transfer in this instance is radiative. These nuances are concerned with how best to maximise the heat transfer from the heat source to the heated object; the placement of heaters within a system; and an assessment of the various techniques and strategies involved in controlling a radiant heating system. The conclusions reached are that: if sized and controlled correctly radiant heating systems offer considerable operational advantages over other types of space heating systems in certain applications, in terms of both economy and controllability. The efficacy of radiant heating systems is affected primarily by the control strategy implemented; secondarily, by the structure of the building into which it is installed; and only marginally by all other factors.

A systems approach to public sector budgeting: the case of the planning, programming, budgeting system for the health and personal social services

The aim of this thesis is to examine the specific contextual factors affecting the applicability and development of the planning, programming, budgeting system (P.P.B.S.) as a systems approach to public sector budgeting. The concept of P.P.B.S. as a systems approach to public sector budgeting will first be developed and the preliminary hypothesis that general contextual factors may be classified under political, structural and cognitive headings will be put forward. This preliminary hypothesis will be developed and refined using American and early British experience. The refined hypothesis will then be tested in detail in the case of the English health and personal social services (H.P.S.S.), The reasons for this focus are that it is the most recent, the sole remaining, and the most significant example in British central government outside of defence, and is fairly representative of non-defence government programme areas. The method of data collection relies on the examination of unpublished and difficult to obtain central government, health and local authority documents, and interviews with senior civil servants and public officials. The conclusion will be that the political constraints on, or factors affecting P.P.B.S., vary with product characteristics and cultural imperatives on pluralistic decision-making; that structural constraints vary with the degree of coincidence of programme and organisation structure and with the degree of controllability of the organisation; and finally, that cognitive constraints vary according to product characteristics, organisational responsibilities, and analytical effort.

Dimensions of perception and recognition of danger

Despite abundant literature on human behaviour in the face of danger, much remains to be discovered. Some descriptive models of behaviour in the face of danger are reviewed in order to identify areas where documentation is lacking. It is argued that little is known about recognition and assessment of danger and yet, these are important aspects of cognitive processes. Speculative arguments about hazard assessment are reviewed and tested against the results of previous studies. Once hypotheses are formulated, the reason for retaining the reportory grid as the main research instrument are outlined, and the choice of data analysis techniques is described. Whilst all samples used repertory grids, the rating scales were different between samples; therefore, an analysis is performed of the way in which rating scales were used in the various samples and of some reasons why the scales were used differently. Then, individual grids are looked into and compared between respondents within each sample; consensus grids are also discussed. the major results from all samples are then contrasted and compared. It was hypothesized that hazard assessment would encompass three main dimensions, i.e. 'controllability', 'severity of consequences' and 'likelihood of occurrence', which would emerge in that order. the results suggest that these dimensions are but facets of two broader dimensions labelled 'scope of human intervention' and 'dangerousness'. It seems that these two dimensions encompass a number of more specific dimensions some of which can be further fragmented. Thus, hazard assessment appears to be a more complex process about which much remains to be discovered. Some of the ways in which further discovery might proceed are discussed.

Dynamic spectrum access in heterogeneous unlicensed wireless networks

Existing wireless systems are normally regulated by a fixed spectrum assignment strategy. This policy leads to an undesirable situation that some systems may only use the allocated spectrum to a limited extent while others have very serious spectrum insufficiency situation. Dynamic Spectrum Access (DSA) is emerging as a promising technology to address this issue such that the unused licensed spectrum can be opportunistically accessed by the unlicensed users. To enable DSA, the unlicensed user shall have the capability of detecting the unoccupied spectrum, controlling its spectrum access in an adaptive manner, and coexisting with other unlicensed users automatically. In this article, we propose a radio system Transmission Opportunity-based spectrum access control protocol with the aim to improve spectrum access fairness and ensure safe coexistence of multiple heterogeneous unlicensed radio systems. In the scheme, multiple radio systems will coexist and dynamically use available free spectrum without interfering with licensed users. Simulation is carried out to evaluate the performance of the proposed scheme with respect to spectrum utilisation, fairness and scalability. Comparing with the existed studies, our strategy is able to achieve higher scalability and controllability without degrading spectrum utilisation and fairness performance.