Showing papers by "Paul Morris published in 2014"

Dynamic Controllability and Dispatchability Relationships

Abstract: An important issue for temporal planners is the ability to handle temporal uncertainty. Recent papers have addressed the question of how to tell whether a temporal network is Dynamically Controllable, i.e., whether the temporal requirements are feasible in the light of uncertain durations of some processes. We present a fast algorithm for Dynamic Controllability. We also note a correspondence between the reduction steps in the algorithm and the operations involved in converting the projections to dispatchable form. This has implications for the complexity for sparse networks.

The Prevalence, Severity, and Impact of Breast Pain in the General Population

Abstract: Breast pain has been investigated in clinical populations; however we have yet to understand the prevalence and severity of this condition in the general population to determine whether more should be done to minimize the impact of this condition on women's quality of life. Therefore, this study investigated the prevalence, severity, and impact of breast pain on quality of life and factors associated with breast pain in a normal population sample. 1,659 females (34.1 ± 13.2 years) completed the Breast Pain Questionnaire online, providing information on demographics, duration, frequency, and severity of breast pain, its association with the menstrual cycle, relieving, and aggravating factors and the impact on quality of life. Over half the sample (51.5%) experienced breast pain, with a severity similar to that reported in clinical populations. There was a higher prevalence of breast pain in older participants, larger breasted participants and those who were less fit and active. Of symptomatic participants, 41% and 35% reported breast pain affecting quality of life measures of sex and sleep and 10% of symptomatic participants had sufferer for over half their lives. The results of this study suggest that breast pain is a significant issue within the general population and yet this is the first study to investigate it. It is concluded that this condition warrants increased investigation, awareness, and treatment. The reported relationship between breast pain and fitness/activity levels may offer an alternative treatment in the form of exercise intervention strategies to reduce breast pain.

Proximity and gaze influences facial temperature: a thermal infrared imaging study.

Abstract: Direct gaze and interpersonal proximity are known to lead to changes in psycho-physiology, behavior and brain function. We know little, however, about subtler facial reactions such as rise and fall in temperature, which may be sensitive to contextual effects and functional in social interactions. Using thermal infrared imaging cameras 18 female adult participants were filmed at two interpersonal distances (intimate and social) and two gaze conditions (averted and direct). The order of variation in distance was counterbalanced: half the participants experienced a female experimenter’s gaze at the social distance first before the intimate distance (a socially “normal” order) and half experienced the intimate distance first and then the social distance (an odd social order). At both distances averted gaze always preceded direct gaze. We found strong correlations in thermal changes between six areas of the face (forehead, chin, cheeks, nose, maxilliary, and periorbital regions) for all experimental conditions and developed a composite measure of thermal shifts for all analyses. Interpersonal proximity led to a thermal rise, but only in the “normal” social order. Direct gaze, compared to averted gaze, led to a thermal increase at both distances with a stronger effect at intimate distance, in both orders of distance variation. Participants reported direct gaze as more intrusive than averted gaze, especially at the intimate distance. These results demonstrate the powerful effects of another person’s gaze on psycho-physiological responses, even at a distance and independent of context.

Non-vitamin K antagonist oral anticoagulants (NOACs): clinical evidence and therapeutic considerations

Abstract: Warfarin, a vitamin K antagonist, is the most widely used oral anticoagulant in the world. It is cheap and effective, but its use is limited in many patients by unpredictable levels of anticoagulation, which increases the risk of thromboembolic or haemorrhagic complications. It also requires regular blood monitoring and dose adjustment. New classes of drugs, non-vitamin K antagonist oral anticoagulants (NOACs), are now supported as alternatives to warfarin. Three NOACs are licensed: dabigatran, a direct thrombin inhibitor, and rivaroxaban and apixaban, antagonists of factor Xa. NOACs do not require routine blood monitoring or dose adjustment. They have a rapid onset and offset of action and fewer food and drug interactions. Current indications include treatment and prophylaxis of venous thromboembolism and prevention of cardioembolic disease in non-valvular atrial fibrillation. Effective antidotes are lacking and some caution must be used in severe renal impairment, but favourable trial evidence has led to their widespread adoption. Research is ongoing, and an increase in their use and indications is expected in the coming years.

The impact of question type and empathy on police interviews with suspects of homicide, filicide and child sexual abuse

Abstract: Conducting interviews with “high-stake” offenders, especially those accused of murder and sexual offences, represents a complex and emotive area of work for police officers. Using an English sample of 59 actual police interviews, the effects of empathy and question type on the amount of investigation-relevant information obtained from interviews with suspects of child murder, child sex offences and adult murder were analysed and compared. No direct effects of empathy on the amount of information elicited were found. However, in interviews classified as empathic, interviewers asked significantly more appropriate questions than they did in interviews classified as non-empathic, and significantly more items of information were elicited from appropriate questions. There was a significant effect of offence type on the number of inappropriate, questions asked, with significantly more inappropriate questions being asked in interviews with suspects of child sex offences than in interviews with suspects of child or adult murder.

An Architecture to Enable Autonomous Control of Spacecraft

Abstract: Autonomy is required for manned spacecraft missions distant enough that light-time communication delays make ground-based mission control infeasible. Presently, ground controllers develop a complete schedule of power modes for all spacecraft components based on a large number of factors. The proposed architecture is an early attempt to formalize and automate this process using on-vehicle computation resources. In order to demonstrate this architecture, an autonomous electrical power system controller and vehicle Mission Manager are constructed. These two components are designed to work together in order to plan upcoming load use as well as respond to unanticipated deviations from the plan. The communication protocol was developed using "paper" simulations prior to formally encoding the messages and developing software to implement the required functionality. These software routines exchange data via TCP/IP sockets with the Mission Manager operating at NASA Ames Research Center and the autonomous power controller running at NASA Glenn Research Center. The interconnected systems are tested and shown to be effective at planning the operation of a simulated quasi-steady state spacecraft power system and responding to unexpected disturbances.

Reconstruction of coronary trees from 3DRA using a 3D+t statistical cardiac prior.

Abstract: A 3D+t description of the coronary tree is important for diagnosis of coronary artery disease and therapy planning. In this paper, we propose a method for finding 3D+t points on coronary artery tree given tracked 2D+t point locations in X-ray rotational angiography images. In order to cope with the ill-posedness of the problem, we use a bilinear model of ventricle as a spatio-temporal constraint on the nonrigid structure of the coronary artery. Based on an energy minimization formulation, we estimate i) bilinear model parameters, ii) global rigid transformation between model and X-ray coordinate systems, and iii) correspondences between 2D coronary artery points on X-ray images and 3D points on bilinear model. We validated the algorithm using a software coronary artery phantom.

Autonomous Spacecraft Communication Interface for Load Planning

Abstract: Ground-based controllers can remain in continuous communication with spacecraft in low Earth orbit (LEO) with near-instantaneous communication speeds. This permits near real-time control of all of the core spacecraft systems by ground personnel. However, as NASA missions move beyond LEO, light-time communication delay issues, such as time lag and low bandwidth, will prohibit this type of operation. As missions become more distant, autonomous control of manned spacecraft will be required. The focus of this paper is the power subsystem. For present missions, controllers on the ground develop a complete schedule of power usage for all spacecraft components. This paper presents work currently underway at NASA to develop an architecture for an autonomous spacecraft, and focuses on the development of communication between the Mission Manager and the Autonomous Power Controller. These two systems must work together in order to plan future load use and respond to unanticipated plan deviations. Using a nominal spacecraft architecture and prototype versions of these two key components, a number of simulations are run under a variety of operational conditions, enabling development of content and format of the messages necessary to achieve the desired goals. The goals include negotiation of a load schedule that meets the global requirements (contained in the Mission Manager) and local power system requirements (contained in the Autonomous Power Controller), and communication of off-plan disturbances that arise while executing a negotiated plan. The message content is developed in two steps: first, a set of rapid-prototyping "paper" simulations are preformed; then the resultant optimized messages are codified for computer communication for use in automated testing.

Determining Mission Effects of Equipment Failures

Abstract: NASA plans call for long duration deep space missions with human crews. Because of light-time delay and other considerations, increased autonomy is needed. Crews on next-generation missions will likely be small, perhaps with as few as four members. A small crew is not likely to possess the full range of expertise needed to deal with unexpected failures and anomalies. Applied artificial intelligence technologies have developed decision support tools with the potential to fill the gap, but these tools need to be integrated to provide a smooth operational capability. In this paper we describe such an integration involving anomaly detection, diagnosis, system effect propagation, and plan repair.