MICPA: a client-assisted channel assignment scheme for throughput enhancement in WLANs

The emergence of high-density wireless local area network (WLAN) deployments in recent years is a testament to the insatiable demands for wireless broadband services. The increased density of WLAN deployments brings with it the potential of increased capacity, extended coverage, and exciting new applications. However, the corresponding increase in contention and interference can significantly degrade throughputs, unless new challenges in channel assignment are effectively addressed. In this paper, a client-assisted channel assignment scheme that can provide enhanced throughput is proposed. A study on the impact of interference on throughput with multiple access points (APs)is first undertaken using a novel approach that determines the possibility of parallel transmissions. A metric with a good correlation to the throughput, i.e., the number of conflict pairs, is used in the client-assisted minimum conflict pairs (MICPA) scheme. In this scheme, measurements from clients are used to assist the AP in determining the channel with the minimum number of conflict pairs to maximize its expected throughput. Simulation results show that the client-assisted MICPA scheme can provide meaningful throughput improvements over other schemes that only utilize the AP’s measurements.

Bias or rationality? The case of UK commercial real estate investment

Purpose – The purpose of this paper is to test the hypothesis that investment decision making in the UK direct property market does not conform to the assumption of economic rationality underpinning portfolio theory. Design/methodology/approach – The developing behavioural real estate paradigm is used to challenge the idea that investor “man” is able to perform with economic rationality, specifically with reference to the analysis of the spatial dispersion of the entire UK “investible stock” and “investible locations” against observed spatial patterns of institutional investment. Location quotients are derived, combining different data sets. Findings – Considerably greater variation in institutional property holdings is found across the UK than would be expected given the economic and stock characteristics of local areas. This appears to provide evidence of irrationality (in the strict traditional economic sense) in the behaviour of institutional investors, with possible herding underpinning levels of investment that cannot be explained otherwise. Research limitations/implications – Over time a lack of distinction has developed between the cause and effect of comparatively low levels of development and institutional property investment across the regions. A critical examination of decision making and behaviour in practice could break this cycle, and could in turn promote regional economic growth. Originality/value – The entire “population” of observations is used to demonstrate the relationships between economic theory and investor performance exploring, for the first time, stock and local area characteristics.

Improving a convection-permitting model simulation of a cold air outbreak

A convection-permitting local-area model was used to simulate a cold air outbreak crossing from the Norwegian Sea into the Atlantic Ocean near Scotland. A control model run based on an operational configuration of the Met Office UKV high-resolution (1.5 km grid spacing) NWP model was compared to satellite, aircraft and radar data. While the control model captured the large-scale features of the synoptic situation, it was not able to reproduce the shallow (<1.5 km) stratiform layer to the north of the open cellular convection. Liquid water paths were found to be too low in both the stratiform and convective cloud regions. Sensitivity analyses including a modified boundary-layer diagnosis to generate a more well-mixed boundary layer and inhibition of ice formation to lower temperatures improved cloud morphology and comparisons with observational data. Copyright © 2013 Royal Meteorological Society and British Crown Copyright, the Met Office

Analysis of red pigments from the Neolithic sites of Çatalhöyük in Turkey and Sheikh-e Abad in Iran

Samples containing red pigment have been collected from two different archaeological sites dating to the Neolithic (Çatalhöyük in Turkey and Sheikh-e Abad in Iran) and have been analysed by a range of techniques. Sub-samples were examined by IR spectroscopy and X-ray diffraction, whilst thin sections were studied using optical polarising microscopy, synchrotron based IR microscopy and environmental scanning electron microscopy with energy dispersive X-ray analysis. Thin layers of red paint in a wall painting from Çatalhöyük were found to contain ochre (hematite and clay) as well as an unexpected component, grains of red and colourless obsidian, which have not been identified in any previous studies of the wall paintings at Çatalhöyük. These small grains of obsidian may have improved the reflective properties of the paint and made the artwork more vivid in the darkness of the buildings. Analysis of a roughly shaped ball of red sediment found on a possible working surface at Sheikh-e Abad revealed that the cause of the red colouring was the mineral hematite, which was probably from a source of terra rossa sediment in the local area. The results of this work suggest it is unlikely that this had been altered by the Neolithic people through mixing with other minerals.

Aluminium and the human breast

The human population is exposed to aluminium (Al) from diet, antacids and vaccine adjuvants, but frequent application of Al-based salts to the underarm as antiperspirant adds a high additional exposure directly to the local area of the human breast. Coincidentally the upper outer quadrant of the breast is where there is also a disproportionately high incidence of breast cysts and breast cancer. Al has been measured in human breast tissues/fluids at higher levels than in blood, and experimental evidence suggests that at physiologically relevant concentrations, Al can adversely impact on human breast epithelial cell biology. Gross cystic breast disease is the most common benign disorder of the breast and evidence is presented that Al may be a causative factor in formation of breast cysts. Evidence is also reviewed that Al can enable the development of multiple hallmarks associated with cancer in breast cells, in particular that it can cause genomic instability and inappropriate proliferation in human breast epithelial cells, and can increase migration and invasion of human breast cancer cells. In addition, Al is a metalloestrogen and oestrogen is a risk factor for breast cancer known to influence multiple hallmarks. The microenvironment is established as another determinant of breast cancer development and Al has been shown to cause adverse alterations to the breast microenvironment. If current useage patterns of Al-based antiperspirant salts contribute to causation of breast cysts and breast cancer, then reduction in exposure would offer a strategy for prevention, and regulatory review is now justified.

Twofold adaptive partition of unity implicits

Partition of Unity Implicits (PUI) has been recently introduced for surface reconstruction from point clouds. In this work, we propose a PUI method that employs a set of well-observed solutions in order to produce geometrically pleasant results without requiring time consuming or mathematically overloaded computations. One feature of our technique is the use of multivariate orthogonal polynomials in the least-squares approximation, which allows the recursive refinement of the local fittings in terms of the degree of the polynomial. However, since the use of high-order approximations based only on the number of available points is not reliable, we introduce the concept of coverage domain. In addition, the method relies on the use of an algebraically defined triangulation to handle two important tasks in PUI: the spatial decomposition and an adaptive polygonization. As the spatial subdivision is based on tetrahedra, the generated mesh may present poorly-shaped triangles that are improved in this work by means a specific vertex displacement technique. Furthermore, we also address sharp features and raw data treatment. A further contribution is based on the PUI locality property that leads to an intuitive scheme for improving or repairing the surface by means of editing local functions.

A note on influence diagnostics in nonlinear mixed-effects elliptical models

This paper provides general matrix formulas for computing the score function, the (expected and observed) Fisher information and the A matrices (required for the assessment of local influence) for a quite general model which includes the one proposed by Russo et al. (2009). Additionally, we also present an expression for the generalized leverage on fixed and random effects. The matrix formulation has notational advantages, since despite the complexity of the postulated model, all general formulas are compact, clear and have nice forms. (C) 2010 Elsevier B.V. All rights reserved.

Teacher renewal: collaboration and collegiality

This paper draws in part on findings gathered for the evaluation of the Victorian Department of Education and Training (DE&T) response to the federal Department of Education, Science and Training (DEST) funded Quality Teacher Progam (QTP). The paper reports on findings from one strategy, the Local Area Project and focuses on aspects of that project that relate to teacher renewal and enhancement of professionalism. The findings suggest that the professional development opportunities offered by participation in Local Area Projects have, through collaboration and collegiality, enhanced teacher professionalism and provided an environment for teacher renewal.

Measuring wellness through interdisciplinary community development: linking the physical, economic and social environment

The aim of this study is to answer the question: Is there evidence that the quality of life of residents in a community that has had community development intervention is different as compared to the quality of life of residents in a nearby community that did not have community development initiatives? This was done by administering community development initiatives in a local area and comparing it to a similar community that did not receive this intervention. The residents of these communities rated the quality of their lives and communities in two purposively selected suburbs in Perth, Western Australia using the Australian Unity Wellbeing Index to measure individual and neighbourhood well-being. The quality of life of residents in both communities is then compared to national averages for quality of life or well-being. Answering this question provides empirical evidence of variation between ratings of quality of life of residents in different communities and highlights the utility of the Wellbeing Index for the evaluation of interdisciplinary community development

The economic performance of transportation infrastructure: an empirical study on the recent development of China

It has been widely recognised that infrastructure systems highly affect the economic development of a country or region. In particular, the quality and quantity of transportation infrastructure have a direct bearing on economic growth in developing countries. Therefore, it is challenging to allocate the infrastructure construction budget across a country so that economic growth as a whole will not be hampered by the lack of infrastructure construction in any local area. In this research, the authors focus on simulating the correlations between economic growth, capital investment and transportation infrastructure construction in China historically and comparing the production and investment indicators at the cross-region based on the statistical data reported from government agencies in China. These computed correlations and indicators are crucial for making financial decisions and investment policies on transportation infrastructure construction at a national level.

LAN cafes: cafes, places of gathering or sites of informal teaching and learning?

Despite the interest of sociologists and educational researchers in Internet café as sites for new cultural and social formations and informal learning, thus far little attention has been paid to the function of café owners, managers and other staff in the mediation and co-construction of those spaces. Drawing from interviews with managers of commercial Internet café in Australia specialising in LAN (Local Area Network) gaming, this article seeks to examine their role and their attitudes more closely; in particular with regard to school-aged users of their facilities. We contend that LAN café are liminal spaces situated at the margins of Australian culture and located at the junctions between home, school and the street, online and offline spaces, work and play. The roles of LAN café managers are similarly ambiguous: in many ways they can be regarded as informal teachers facilitating the process of informal learning.

Water, weeds and autumn leaves : learning to be drier in the alpine region

Our paper explores how and what adults living and working in the Alpine region of Victoria understand and are learning about the changes to water availability, in a time when the response to water availability is subject to extensive debate and policy attention. Interviews for this study were conducted in the towns of Bright and Mount Beauty, with participants drawn from across the Alpine region. The interviews focused on what local stakeholders from the Alpine region understood about water availability in the region and how and what they had learned about living and working with climatic changes in their local area.

The findings of our study see that there was evidence of a strong understanding of the direct and indirect impact of climate change on participants' local community area. The study also sees evidence of learning through a community 'frames of reference' as outlined by Berkhout, Hertin and Dann et al.

Teaching Zambian traditional birth attendants to monitor growth of infants : evaluation of an education program

The high infant mortality in Zambia is largely attributable to malnutrition. It is exacerbated by the inability of mothers to recognise threats to nutritional status and take corrective action. Advice in ‘Health Centres’ is often inaccessible to mothers. The Traditional Birth Attendants (TBAs) work with pregnant women in local communities, and the purpose of this study was to develop and implement an educationprogram in growth monitoring and nutrition for the TBAs and then to evaluate its effects. Twenty five TBAs from two peri-urban areas of Kitwe were enrolled in this pilot study and eighteen completed the program. The researcher developed and taught a program to the TBAs over ten days. A pretest was given before the teaching program to enable the researcher to obtain information about the knowledge and skills of the TBAs. Following the teaching program the TBAs were re-tested, with the same questionnaire. Focus groups were conducted to enable the TBA to provide information on the teaching materials and the education program. The TBAs then returned to their communities and put into practice the skills and knowledge they had learned for six months. Their practice was monitored by a trained Public Health Nurse. The researcher also surveyed 38 pregnant women about their knowledge of growth monitoring and nutrition before the TBAs went into the field to work with their local communities. The same questionnaire used with the pregnant women was administered to 38 new mothers with children aged 0 to 6 months to gain information of their knowledge and skills following the work of the TBAs. The program was evaluated by assessing the extent to which TBAs knowledge and skills were increased, the knowledge and understanding of a selection of their clients and the rates of malnutrition of infants in the area under study. The results from the research clearly indicated that the teaching program on growth monitoring and nutrition given to the selected group of TBAs had a positive effect on their knowledge and skills. It was found that the teaching developed their knowledge, practical skills, evaluative skills. That they were able to give infants’ mothers sound advice regarding their children’s nutrition was revealed by the mother’s increased knowledge and the decrease in numbers of malnourished children in the study areas at the conclusion of the research. The major outcomes from the study are: that Zambian TBAs can be taught to carry out an expanded role; field experience is a key factor in the teaching program; making advice available in local communities is important; and preliminary data on the Zambian experience were generated. Recommendations are: The pilot program should be expanded with continuing support from the Health Department. Similar educational programs should be introduced into other areas of Zambia with support from the Ministry of Health. That in administering a teaching program: Sufficient time must be allocated to practical work to allow poorly educated women to attain the basic skills needed to master the complex skills required to competently reduce faltering in their communities. The teaching materials to illustrate nutritional principles for feeding programs must be developed to suite locally available foods and conditions. Methods of teaching should suit the local area, for example, using what facilities are locally available. The timing of the teaching program should be suitable for the TBAs to attend. This may vary from area to area, for example it may be necessary to avoid times traditionally given to fetching water or working in the fields. For similar reasons, the venue for the teaching program should be suitable to the TBAs. The teachers should go into the TBAs’ community rather than causing disruption of the TBAs’ day by expecting them to go to the teacher. Data should be collected from a larger group of TBAs and clients to enable sophisticated statistical analysis to complement data from this pilot program. The TBAs should be given recognition for their work and achievement. This is something which they asked for. They do not ask for payment, rather acknowledgment through regular follow up and approbation.

Climate change in the Victorian Alps : can VET be a change agent?

Of all the factors contributing to turbulent times in Australia, climate change is one that offers both challenges and opportunities for VET. In a time when the response to water availability is subject to ‘extensive debate and policy attention’, our presentation explores what adults living and working in the Alpine region of Victoria understand about the changes to water availability, and what they have learned about adapting to significant climatic changes in their local area. Interviews were conducted in the towns of Bright, Mount Beauty and Albury, with participants from across the Alpine region. Our study found evidence of a strong understanding of the direct impact of climate change on participants’ local community area, and a keen desire to learn about adaptation to change. In addition to an identified need for more information around climate change issues and projected impacts in general, participants saw practical hands-on water education strategies as an important way to educate people to help themselves. Conversations about where or how people learned to adapt to change were broad ranging, and clearly connected to the participants’ backgrounds, livelihoods or where they were situated. This raised the question of what responses VET might develop to address these identified learning needs. Major local industries
of tourism, agriculture, water harvesting and land care are all covered by national Training Packages that include industry- specific units of competence to support learning to live and work in an environmentally sustainable way. In addition, the national Employability Skills framework offers opportunities to build climate change awareness and adaptation into units of competency where they may not be explicitly incorporated. Our presentation will outline the opportunities for VET to act as a change agent in this and other Australian communities impacted by climate change.

Associations between intrapersonal and neighborhood environmental characteristics and cycling for transport and recreation in adults : baseline results from the RESIDE study

Background: This study investigated the relationship between individual and neighborhood environmental factors and cycling for transport and for recreation among adults living in Perth, Western Australia.
Methods: Baseline cross-sectional data from 1813 participants (40.5% male; age range 18 to 78 years) in the Residential Environment (RESIDE) project were analyzed. The questionnaire included information on cycling behavior and on cycling-specific individual, social environmental, and neighborhood environmental attributes. Cycling for transport and recreation were dichotomized as whether or not individuals cycled in a usual week.
Results: Among the individual factors, positive attitudes toward cycling and perceived behavioral control increased the odds of cycling for transport and for recreation. Among the neighborhood environmental attributes, leafy and attractive neighborhoods, access to bicycle/walking paths, the presence of traffic slowing devices and having many 4-way street intersections were positively associated with cycling for transport. Many alternative routes in the local area increased the odds of cycling for recreation.
Conclusions: Effective strategies for increasing cycling (particularly cycling for transport) may include incorporating supportive environments such as creating leafy and attractive neighborhood surroundings, low traffic speed, and increased street connectivity, in addition to campaigns aimed at strengthening positive attitudes and confidence to cycle.