Parallel I/O scheduling in the presence of data duplication on multiprogrammed cluster computing systems

The widespread adoption of cluster computing as a high performance computing platform has seen the growth of data intensive scientific, engineering and commercial applications such as digital libraries, climate modeling, computational chemistry, computational fluid dynamics and image repositories. However, I/O subsystem performance has not been keeping pace with processor and memory performance, and is fast becoming the dominant factor in overall system performance.  Thus, parallel I/O has become a necessity in the face of performance improvements in other areas of computing systems. This paper addresses the problem of parallel I/O scheduling on cluster computing systems in the presence of data replication.  We propose two new I/O scheduling algorithms and evaluate the relative performance of the proposed policies against two existing approaches.  Simulation results show that the proposed policies perform substantially better than the baseline policies.

Interactive television and the role of affective usability

This paper explores the importance of designing interfaces that evoke positive feelings in the user as they interact with the interface. The use of interactive television (iTV) and affective usability illustrate how usability paradigms shift as new technology is developed. Traditional television is a more passive medium than iTV and the role of the user (or viewer) varies significantly. iTV requires more of the user and to be an active contributor because of the more interactive interaction style. Interface designers need to constantly define better ways of developing interfaces that are not only usable, but also enjoyable to use.

Data collection for global scheduling in the GENESIS system

In order to schedule parallel processes on available computers there is a need to collect information about different cluster resources. Currently, global scheduling of parallel processes of applications takes into consideration mainly processor load and only in a small number of projects memory utilization. Communication costs, which are high in clusters, are practically neglected. The aim of this paper is to report on our study into cluster parameter measurements, in particular those, which characterize communication costs, the development of the resource discovery server and its initial testing through the study of the influence of communication costs on parallel application performance.

Physical activity and television viewing in relation to risk and undiagnosed abnormal glucose metabolism in adults

OBJECTIVE--The goal of this study was to assess the associations of physical activity time and television (TV) time with risk of "undiagnosed" abnormal glucose metabolism in Australian adults.

RESEARCH DESIGN AND METHODS--This population-based cross-sectional study using a stratified cluster design involving 42 randomly selected Census Collector Districts across Australia included 8,299 adults aged 25 years or older who were free from new type 2 diabetes and self-reported ischemic disease and did not take lipid lowering or antihypertensive drugs. Abnormal glucose metabolism (impaired fasting glycetnia [IFG], impaired glucose tolerance [IGT], or new type 2 diabetes) was based on an oral glucose tolerance test Self reported physical activity time and TV time (previous week) were assessed using interviewer administered questionnaires.

RESULTS--Alter adjustment for known confounders and TV time, the odds ratio (OR) of having abnormal glucose metabolism was 0.62 (95% CI 0.41-0.96) in men and 0.71 (0.501.00) in women for those engaged in physical activity [greater than or equal to] 2.5 h/week compared with those who were sedentary (0 h/week). The ORs of having abnormal glucose metabolism were 1.16 (0.791.70) in men and 1.49 (1.12-1.99) in women who watched TV > 14 h/week compared with those who watched [less than or equal to] 7.0 h/week. Higher TV viewing (> 14 h/week) was also associated with an increased risk of new type 2 diabetes in men and women and IGT in women compared with those watching < 14 h/week. Total physical activity of [greater than or equal to] 2.5 h/week was associated with a reduced risk of IFG, IGT, and new type 2 diabetes in both sexes: however, only the association with IGT in women was statistically significant.

CONCLUSIONS--These findings suggest a protective effect of physical activity and a deleterious effect of TV time on the risk of abnormal glucose metabolism in adults. Population strategies to reduce risk of abnormal glucose metabolism should focus on reducing sedentary behaviors such as TV time, as well as increasing physical activity.

The effects of television advertisements for junk food versus nutritious food on children's food attitudes and preferences

Television (TV) food advertising has attracted criticism for its potential role in promoting unhealthy dietary practices among children. Content analyses indicate junk food advertising is prevalent on Australian children's TV; healthy eating is rarely promoted. This paper presents (a) a cross-sectional survey examining associations between children's regular TV viewing habits and their food-related attitudes and behaviour; and (b) an experiment assessing the impact of varying combinations of TV advertisements (ads) for unhealthy and healthy foods on children's dietary knowledge, attitudes and intentions. The experimental conditions simulated possible models for regulating food ads on children's TV. Participants were 919 grade five and six students from schools in Melbourne, Australia. The survey showed that heavier TV use and more frequent commercial TV viewing were independently associated with more positive attitudes toward junk food; heavier TV use was also independently associated with higher reported junk food consumption. The experiment found that ads for nutritious foods promote selected positive attitudes and beliefs concerning these foods. Findings are discussed in light of methodological issues in media effects research and their implications for policy and practice. It is concluded that changing the food advertising environment on children's TV to one where nutritious foods are promoted and junk foods are relatively unrepresented would help to normalize and reinforce healthy eating.

Stability of television viewing and electronic game/computer use in a prospective cohort study of Australian children: relationship with body mass index

Background
While much cross-sectional data is available, there have been few longitudinal investigations of patterns of electronic media use in children. Further, the possibility of a bi-directional relationship between electronic media use and body mass index in children has not been considered. This study aimed to describe longitudinal patterns of television viewing and electronic game/computer use, and investigate relationships with body mass index (BMI).
Methods
This prospective cohort study was conducted in elementary schools in Victoria, Australia. 1278 children aged 5–10 years at baseline and 8–13 years at follow-up had their BMI calculated, from measured height and weight, and transformed to z-scores based on US 2000 growth data. Weight status (non-overweight, overweight and obese) was based on international BMI cut-off points. Weekly television viewing and electronic game/computer use were reported by parents, these were summed to generate total weekly screen time. Children were classified as meeting electronic media use guidelines if their total screen time was ≤14 hrs/wk.
Results
Electronic media use increased over the course of the study; 40% met guidelines at baseline but only 18% three years later. Television viewing and electronic game/computer use tracked moderately and total screen time was positively associated with adiposity cross-sectionally. While weaker relationships with adiposity were observed longitudinally, baseline z-BMI and weight status were positively associated with follow-up screen time and baseline screen time was positively associated with z-BMI and weight status at follow-up. Children who did not meet guidelines at baseline had significantly higher z-BMI and were more likely to be classified as overweight/obese at follow-up.

Conclusion
Electronic media use in Australian elementary school children is high, increases with age and tracks over time. There appears to be a bi-directional association suggesting that interventions targeting reductions in either screen time or adiposity may have a positive effect on both screen time and adiposity.

Association of television viewing with fasting and 2-h postchallenge plasma glucose levels in adults without diagnosed diabetes

OBJECTIVE—We examined the associations of television viewing time with fasting plasma glucose (FPG) and 2-h postchallenge plasma glucose (2-h PG) levels in Australian adults.

RESEARCH DESIGN AND METHODS—A total of 8,357 adults aged >35 years who were free from diagnosed diabetes and who attended a population-based cross-sectional study (Australian Diabetes, Obesity and Lifestyle Study [AusDiab]) were evaluated. Measures of FPG and 2-h PG were obtained from an oral glucose tolerance test. Self-reported television viewing time (in the previous week) was assessed using an interviewer-administered questionnaire. Homeostasis model assessment (HOMA) of insulin sensitivity (HOMA-%S) and ß-cell function (HOMA-%B) were calculated based on fasting glucose and insulin concentrations.

RESULTS—After adjustment for confounders and physical activity time, time spent watching television in women was positively associated with 2-h PG, log fasting insulin, and log HOMA-%B and inversely associated with log HOMA-%S (P < 0.05) but not with FPG. No significant associations were observed with glycemic measures in men. The ß-coefficients across categories of average hours spent watching television per day (<1.0, 1.0–1.9, 2.0–2.9, 3.0–3.9, and ≥4.0) for 2-h PG in women were 0 (reference), 0.009, 0.047, 0.473, and 0.501, respectively (P for trend = 0.02).

CONCLUSIONS—Our findings highlight the unique deleterious relationship of sedentary behavior (indicated by television viewing time) and glycemic measures independent of physical activity time and adiposity status. These relationships differed according to sex and type of glucose measurement, with the 2-h PG measure being more strongly associated with television viewing. The findings suggest an important role for reducing sedentary behavior in the prevention of type 2 diabetes and cardiovascular disease, especially in women.

Association between the family environment and television viewing in Australian children

Aim: To describe the time children spend watching television (TV) and to assess associations between TV viewing time, the family environment and weight status.

Methods: Parents reported the amount of time children watched TV/video both for ‘the previous school day’ and ‘usually’ and described aspects of the family environment influencing TV access as part of a large cross-sectional study in the Barwon South-western region of Victoria, Australia. Child weight status was  based on measured height and weight. All data were collected in 2003/2004.

Results: A total of 1926 children aged 4–12 years participated. Parent-reported mean ± SE TV time for the previous school day was 83 ± 1.5 min. Children who lived in a family with tight rules governing TV viewing time (22%), or who never watched TV during dinner (33%), or had only one TV in the household (23%) or had no TV in their bedroom (81%) had significantly less TV time than their  counterparts. Overweight or obese children had more TV time than healthy weight children 88 ± 2.9 versus 82 ± 1.7 min per day (P = 0.04). They were also more likely to live in a household where children had a TV in their bedroom than healthy weight children (25% vs. 17%, P < 0.001).

Conclusion: Strategies to reduce TV time should be included as part of broader strategies to prevent childhood obesity. They should include messages to parents about not having a TV in children’s bedrooms, encouraging family rules restricting TV viewing, and not having the TV on during dinner.

Evaluating the EASY-backfill job scheduling of static workloads on clusters

This research aims at improving our understanding of backfilling job scheduling algorithms. The most frequently used algorithm, EASY-backfilling, was selected for a performance evaluation by scheduling static workloads of parallel jobs on a computer cluster. To achieve the aim, we have developed a batch job scheduler for Linux clusters, implemented several scheduling algorithms including ARCA and EASY-Backfilling, and carried out their performance evaluation by running well known MPI applications on a real cluster. Our performance evaluation carried out for EASY-Backfilling serves two purposes. First, the performance results obtained from our evaluation can be used to validate other researcherspsila results generated by simulation, and second, the methodology used in our evaluation has alleviated many problems existed in the simulations presented in the current literature.

Sensor node activity scheduling approach

Sensor networks, once deployed, are expected to continue to function unmanned. However, energy of the sensors is typically unrenewable thus making it a very scarce resource. Therefore, in order to extend the life of the sensor networks for the duration of a particular mission, energy has to be managed wisely. In this paper, we consider the problem of energy conservation for grid-based sensor networks. A wireless sensor network architecture that is based on mobile base station is presented. Based on this architecture, we propose an asynchronous duty-cycle scheduling scheme for extending the lifetime of the grid-based wireless sensor networks.

Family and home correlates of television viewing in 12-13 year old adolescents: the Nepean study

Background
Few young people meet television viewing guidelines.
Purpose
To determine the association between factors in the family and home environment and watching television, including videos and DVDs, in early adolescence.
Methods
Cross-sectional, self-report survey of 343 adolescents aged 12–13 years (173 girls), and their parents (338 mothers, 293 fathers). Main measures were factors in the family and home environment potentially associated with adolescents spending ≥ 2 hours per day in front of the television. Factors examined included family structure, opportunities to watch television/video/DVDs, perceptions of rules and regulations on television viewing, and television viewing practices.
Results
Two-thirds of adolescents watched ≥ 2 hours television per day. Factors in the family and home environment associated with adolescents watching television ≥ 2 hours per day include adolescents who have siblings (Adjusted Odds Ratio [95%CI] AOR = 3.0 [1.2, 7.8]); access to pay television (AOR = 2.0 [1.1, 3.7]); ate snacks while watching television (AOR = 3.1 [1.8, 5.4]); co-viewed television with parents (AOR = 2.3 [1.3, 4.2]); and had mothers who watched ≥ 2 hours television per day (AOR = 2.4 [1.3, 4.6]).
Conclusion
There are factors in the family and home environment that influence the volume of television viewed by 12–13 year olds. Television plays a central role in the family environment, potentially providing a means of recreation among families of young adolescents for little cost. Interventions which target family television viewing practices and those of parents, in particular, are more likely to be effective than interventions which directly target adolescent viewing times.

Television, computer use and body mass index in Australian primary school children

Objective: To investigate relationships between children's body mass index (BMI) and parent reports of children's television and video game/computer habits, controlling for other potential risk factors for paediatric obesity.

Methods: Child BMI was calculated from measured height and weight collected in 1997 as part of a large, representative, cross-sectional study of children in Victoria, Australia. Parents reported the amount of time children watched television and used video games/computers, children's eating and activity habits, parental BMI and sociodemographic details.

Results: A total of 2862 children aged 5−13 years participated. Child mean BMI z-score was significantly related to television (F = 10.2₃, P < 0.001) but not video game/computer time (F = 2.2₃, P = 0.09), but accounted for only 1 and 0.2% of total BMI variance, respectively. When parental BMI, parental education, number of siblings, food intake, organized exercise and general activity level were included, television ceased to be independently significantly related to child BMI. Using adjusted logistic regression, the odds of being overweight and obese generally increased with increasing television viewing. No relationship was found for video game/computer use.
Conclusions: A small proportion of variance in child BMI was related to television, but not video game/computer time. This was far outweighed by the influence of other variables. Causal pathways are likely to be complex and interrelated.