Dynamic minimal spanning tree routing protocol for large wireless sensor networks

Hundreds or thousands of wireless sensor nodes with limited energy resource are randomly scattered in the observation fields to extract the data messages for users. Because their energy resource cannot be recharged, energy efficiency becomes one of the most important problems. LEACH is an energy efficient protocol by grouping nodes into clusters and using cluster heads (CH) to fuse data before transmitting to the base station (BS). BCDCP improves LEACH by introducing a minimal spanning tree (MST) to connect CHs and adopting iterative cluster splitting algorithm to choose CHs or form clusters. This paper proposes another innovative cluster-based routing protocol named dynamic minimal spanning tree routing protocol (DMSTRP), which improves BCDCP by introducing MSTs instead of clubs to connect nodes in clusters. Simulation results show that DMSTRP excels LEACH and BCDCP in terms of both network lifetime and delay when the network size becomes large.

Career facilitators and obstacles of Australian football development coaches

Career development is considered integral to the success of individuals, organisations and professions. Coaches play a vital role in the success of sport, yet little is known about their career development. Despite the advances in career development for athletes, there has been very little scholarly attention, nor resources provided for coach career development, especially for coaches working outside elite and professional sport. This pilot study explored the career development facilitators and obstacles of junior development Australian football coaches. Semi-structured interviews were used to collect data on the career development of six practicing junior development Australian football coaches. These six (of only 12 employed) coaches worked in the main elite junior development league for Australian football, the Transport Accident Commission Cup. The themes that emerged from the data revealed that the career development of junior development Australian football coaches was facilitated first by their high motivation to coach because of their enjoyment of seeing young players develop and transition into the elite competition. The second facilitator was the coach’s awareness of their career development needs and their willingness to do their own career development despite limited opportunity, guidance or support. The key obstacles to Transport Accident Commission Cup coach career development included a lack of opportunity to spend time at elite clubs to observe and interact with elite coaches; a lack of time due to having a non-coaching job to financially support their coaching work and their family as well; the high demands of the coaching role had a negative impact on their work–life balance and often conflicted with time they would rather spend with their families; and finally, the lack of institutional support for coaches who were asked to work long hours for low wages and little reward despite their vital role in the elite player development pathway for the Australian Football League. This research suggests that junior development Australian football coaches have a clear understanding of their role and how it changes as their career develops; however, the coaches are limited by external forces in their career development. Junior development Australian football coaches are vital for Australian Football League development; however, there is disconnection between Australian Football League goals and their capacity to nurture elite athletes into the sport’s system due to part-time coaching roles, limited resources and few opportunities for coaches to develop their careers.

The association between alcohol outlet density and alcohol use among urban and regional Australian adolescents

AIMS: While recent evidence suggests that higher alcohol outlet density is associated with greater alcohol use among adolescents, influence of the four main outlet types on youth drinking within urban and regional communities is unknown. This study provides the first investigation of this relationship. DESIGN: Repeated cross-sectional surveys with random samples of secondary students clustered by school. Mixed-effects logistic regression analyses examined the association between each outlet type and the drinking outcomes, with interaction terms used to test urban/regional differences. SETTING: Australia, 2002-11. PARTICIPANTS: Respondents participating in a triennial survey (aged 12-17 years); 44 897 from urban settings, 23 311 from regional settings. MEASUREMENTS: The key outcome measures were past month alcohol use, risky drinking among all students and risky drinking among past week drinkers. For each survey year, students were assigned a postcode-level outlet density (number of licences per 1000 population) for each outlet type (general, on-premise, off-premise, clubs). FINDINGS: Interaction terms revealed a significant association between off-premises outlet density and risky drinking among all adolescents in urban (odds ratio = 1.36, 95% confidence interval CI = 1.05-1.75, P < 0.05) but not regional areas. Similarly, club density was associated with the drinking outcomes in urban communities only. General and on-premises density was associated with alcohol use and risky drinking among all adolescents. CONCLUSIONS: Higher densities of general, on- and off-premises outlets in an adolescent's immediate neighbourhood are related to increased likelihood of alcohol consumption among all adolescents. The density of licensed clubs is associated more strongly with drinking for urban than for regional adolescents.

Ethnically differentiated architecture in a global world

Cities have been substantially affected and many transformed by increasing cultural diversity resulting from waves of migration. The central role and dynamism of cultural diversity evident in retail and commercial streetscapes has dominated the debates on global and contemporary urban culture (Sandercock 2003). Architecture has been implicit as the background to these debates, but restaurants, residential, religious, institutional and community buildings, ethnic clubs and reception centres, constructed and adapted by migrant communities, provide evidence of the material change of the architecture of localities and neighbourhoods.