What influences student participation in asynchronous online discussions

Asynchronous online discussions are widely used in online and blended learning courses. Participation by adult learners can be encouraged by the contributions of teachers, and when online groups are given well-structured tasks that are assessed. The introduction of such discussions to a pre-existing short course in mentorship for qualified health care professionals offered an opportunity to compare participation by different groups studying concurrently. This was done by counting numbers of student contributions to twenty-four different online groups, regardless of length or content. This showed that the contribution of teachers was not an important factor in influencing student participation, though individual students who contributed prolifically tended to encourage their fellow group members to contribute more. These results may not be generalizable: the course was short, the discussions focused on a well-structured and assessed task, and the learners were mature

A compensatory algorithm for the slow-down effect on constant-time-separation approaches

In seeking methods to improve airport capacity, the question arose as to whether an electronic display could provide information which would enable the pilot to be responsible for self-separation under instrument conditions to allow for the practical implementation of reduced separation, multiple glide path approaches. A time based, closed loop algorithm was developed and simulator validated for in-trail (one aircraft behind the other) approach and landing. The algorithm was designed to reduce the effects of approach speed reduction prior to landing for the trailing aircraft as well as the dispersion of the interarrival times. The operational task for the validation was an instrument approach to landing while following a single lead aircraft on the same approach path. The desired landing separation was 60 seconds for these approaches. An open loop algorithm, previously developed, was used as a basis for comparison. The results showed that relative to the open loop algorithm, the closed loop one could theoretically provide for a 6 pct. increase in runway throughput. Also, the use of the closed loop algorithm did not affect the path tracking performance and pilot comments indicated that the guidance from the closed loop algorithm would be acceptable from an operational standpoint. From these results, it is concluded that by using a time based, closed loop spacing algorithm, precise interarrival time intervals may be achievable with operationally acceptable pilot workload

Social capital and health: the problematic roles of social networks and social surveys

Social capital, social networks, social support and health have all been linked, both theoretically and empirically. However, the relationships between them are far from clear. Surveys of social capital and health often use measures of social networks and social support in order to measure social capital, and this is problematic for two reasons. First, theoretical assumptions about social networks and social support being part of social capital are contestable. Second, the measures used inadequately reflect the complexity and ambivalence of social relationships, often assuming that all social ties and contacts are of similarly value, are mutually reinforcing, and, in some studies, are based on neighbourhoods. All these assumptions should be questioned. Progress in our understanding requires more qualitative research and improved choice of indicators in surveys; social network analysis may be a useful source of methodological and empirical insight

Effect of display size on utilization of traffic situation display for self-spacing task

The weather radar cathode ray tube (CRT) is the prime candidate for presenting cockpit display of traffic information (CDTI) in current, conventionally equipped transport aircraft. Problems may result from this, since the CRT size is not optimized for CDTI applications and the CRT is not in the pilot's primary visual scan area. The impact of display size on the ability of pilots to utilize the traffic information to maintain a specified spacing interval behind a lead aircraft during an approach task was studied. The five display sizes considered are representative of the display hardware configurations of airborne weather radar systems. From a pilot's subjective workload viewpoint, even the smallest display size was usable for performing the self spacing task. From a performane viewpoint, the mean spacing values, which are indicative of how well the pilots were able to perform the task, exhibit the same trends, irrespective of display size; however, the standard deviation of the spacing intervals decreased (performance improves) as the display size increased. Display size, therefore, does have a significant effect on pilot performance

Guidance, flight mechanics and trajectory optimization. Volume 2 - Observation theory and sensors

Observation theory and sensors applicable to navigation of boost and space vehicle

A Non-Probabilistic Model of Relativised Predictability in Physics

Little effort has been devoted to studying generalised notions or models of (un)predictability, yet is an important concept throughout physics and plays a central role in quantum information theory, where key results rely on the supposed inherent unpredictability of measurement outcomes. In this paper we continue the programme started in [1] developing a general, non-probabilistic model of (un)predictability in physics. We present a more refined model that is capable of studying different degrees of "relativised" unpredictability. This model is based on the ability for an agent, acting via uniform, effective means, to predict correctly and reproducibly the outcome of an experiment using finite information extracted from the environment. We use this model to study further the degree of unpredictability certified by different quantum phenomena, showing that quantum complementarity guarantees a form of relativised unpredictability that is weaker than that guaranteed by Kochen-Specker-type value indefiniteness. We exemplify further the difference between certification by complementarity and value indefiniteness by showing that, unlike value indefiniteness, complementarity is compatible with the production of computable sequences of bits.Comment: 10 page