Bounding inconsistency using a novel threshold metric for dead reckoning update packet generation

Human-to-human interaction across distributed applications requires that sufficient consistency be maintained among participants in the face of network characteristics such as latency and limited bandwidth. The level of inconsistency arising from the network is proportional to the network delay, and thus a function of bandwidth consumption. Distributed simulation has often used a bandwidth reduction technique known as dead reckoning that combines approximation and estimation in the communication of entity movement to reduce network traffic, and thus improve consistency. However, unless carefully tuned to application and network characteristics, such an approach can introduce more inconsistency than it avoids. The key tuning metric is the distance threshold. This paper questions the suitability of the standard distance threshold as a metric for use in the dead reckoning scheme. Using a model relating entity path curvature and inconsistency, a major performance related limitation of the distance threshold technique is highlighted. We then propose an alternative time—space threshold criterion. The time—space threshold is demonstrated, through simulation, to perform better for low curvature movement. However, it too has a limitation. Based on this, we further propose a novel hybrid scheme. Through simulation and live trials, this scheme is shown to perform well across a range of curvature values, and places bounds on both the spatial and absolute inconsistency arising from dead reckoning

Exploring the use of local consistency measures as thresholds for dead reckoning update packet generation

Human-to-human interaction across distributed applications requires that sufficient consistency be maintained among participants in the face of network characteristics such as latency and limited bandwidth. Techniques and approaches for reducing bandwidth usage can minimize network delays by reducing the network traffic and therefore better exploiting available bandwidth. However, these approaches induce inconsistencies within the level of human perception. Dead reckoning is a well-known technique for reducing the number of update packets transmitted between participating nodes. It employs a distance threshold for deciding when to generate update packets. This paper questions the use of such a distance threshold in the context of absolute consistency and it highlights a major drawback with such a technique. An alternative threshold criterion based on time and distance is examined and it is compared to the distance only threshold. A drawback with this proposed technique is also identified and a hybrid threshold criterion is then proposed. However, the trade-off between spatial and temporal inconsistency remains

Older and wiser? Men’s and women’s accounts of drinking in early mid-life

Most qualitative research on alcohol focuses on younger rather than older adults. To explore older people’s relationship with alcohol, we conducted eight focus groups with 36 men and women aged 35 to 50 years in Scotland, UK. Initially, respondents suggested that older drinkers consume less alcohol, no longer drink to become drunk and are sociable drinkers more interested in the taste than the effects of alcohol. However, as discussions progressed, respondents collectively recounted recent drunken escapades, challenged accounts of moderate drinking, and suggested there was still peer pressure to drink. Some described how their drinking had increased in mid-life but worked hard discursively to emphasise that it was age and stage appropriate (i.e. they still met their responsibilities as workers and parents). Women presented themselves as staying in control of their drinking while men described going out with the intention of getting drunk (although still claiming to meet their responsibilities). While women experienced peer pressure to drink, they seemed to have more options for socialising without alcohol than did men. Choosing not to drink alcohol is a behaviour that still requires explanation in early mid-life. Harm reduction strategies should pay more attention to drinking in this age group

Risk of critical illness among patients with solid cancers: a population-based observational study of 118,541 adults

Importance: Critical illness may be a potential determinant of cancer outcomes and geographic variations, but its role has not been described before. Objective: To determine the incidence of admission to intensive care units (ICUs) within 2 years following cancer diagnosis. Design, Setting, and Participants: This was a retrospective observational study using cancer registry data in 4 datasets from 2000 to 2009 with linked ICU admission data from 2000 to 2011, in the West of Scotland region of the United Kingdom (population, 2.4 million; all 16 ICUs within the region). All 118 541 patients (≥16 years) diagnosed as having solid (nonhematological) cancers. Their median age was 69 years, and 52.0% were women. Main Outcomes and Measures: Demographic and clinical variables associated with admission to an ICU and death in an ICU. Results: A total of 118 541 patients met the study criteria. Overall, 6116 patients (5.2% [95% CI, 5.0%-5.3%]) developed a critical illness and were admitted to an ICU within 2 years. Risk of critical illness was highest at ages 60 to 69 years and higher in men. The cumulative incidence of critical illness was greatest for small intestinal (17.2% [95% CI, 13.3%-21.8%]) and colorectal cancers (16.5% [95% CI, 15.9%-17.1%]). The risk following breast cancer was low (0.8% [95% CI, 0.7%-1.0%]). The percentage who died in ICUs was 14.1% (95% CI, 13.3%-15.0%), and during the hospital stay, 24.6% (95% CI, 23.5%-25.7%). Mortality was greatest among emergency medical admissions and lowest among elective surgical patients. The risk of critical illness did not vary by socioeconomic circumstances, but mortality was higher among patients from deprived areas. Conclusions and Relevance: In this study, about 1 in 20 patients experienced a critical illness resulting in ICU admission within 2 years of cancer diagnosis. The associated high mortality rate may make a significant contribution to overall cancer outcomes

Design implementation and evaluation of a tablet-based student response system for an engineering classroom

Student response systems (SRSs) have generated significant debate and discussion in the educational research literature in the past decade. It is well known that they offer several important advantages including encouraging student interaction, offering anonymous and instant student feedback and improving the student learning experience. While several different types of such systems exist, they nevertheless remain limited in their input capabilities. In particular, they typically only allow for multiple-choice style responses, although some devices do cater for numerical and textual input. However, most of the available SRSs do not allow for freeform input such as mathematical equations, graphical drawings or circuit diagrams. This is of particular relevance to Engineering and Science disciplines where such information is core to the student learning. The approach to solving a problem is often as important, if not more so, than the actual final answer itself. This paper presents a classroom response system that allows for freeform input and operates on any smart media device with a touch interface and that employs the Android operating system, such as everyday smart phones and tablets. The proposed system involves three different components, namely a student application that allows for sketch capabilities, a lecturer application that allows for the viewing and marking of multiple student sketches and a cloud service for the exchange of messages. In addition, this proposed system was evaluated by a class of engineering students at NUI Maynooth, the results of which are presented within

Power loss and demagnetization research for high speed permanent magnet electrical machine

High speed permanent magnet machines (HSPMMs) have earned extensive interests in industrial application such as compressors, centrifuges and pumps due to their dramatic advantages of high power density, high efficiency and compact size [1-2]

Harnessing brain power at NUI Maynooth

The Department of Electronic Engineering at NUI Maynooth is involved in exciting interdisciplinary work in the biomedical, digital signal processing, control and electronic systems areas. Here Tomas Ward, Seán McLoone and Shirley Coyle highlight three specific projects