Secure and energy-efficient data aggregation with malicious aggregator identification in wireless sensor networks

Data aggregation in wireless sensor networks is employed to reduce the communication overhead and prolong the network lifetime. However, an adversary may compromise some sensor nodes, and use them to forge false values as the aggregation result. Previous secure data aggregation schemes have tackled this problem from different angles. The goal of those algorithms is to ensure that the Base Station (BS) does not accept any forged aggregation results. But none of them have tried to detect the nodes that inject into the network bogus aggregation results. Moreover, most of them usually have a communication overhead that is (at best) logarithmic per node. In this paper, we propose a secure and energy-efficient data aggregation scheme that can detect the malicious nodes with a constant per node communication overhead. In our solution, all aggregation results are signed with the private keys of the aggregators so that they cannot be altered by others. Nodes on each link additionally use their pairwise shared key for secure communications. Each node receives the aggregation results from its parent (sent by the parent of its parent) and its siblings (via its parent node), and verifies the aggregation result of the parent node. Theoretical analysis on energy consumption and communication overhead accords with our comparison based simulation study over random data aggregation trees.

Activity and energy expenditure in older people playing active video games

OBJECTIVES: To quantify energy expenditure in older adults playing interactive video games while standing and seated, and secondarily to determine whether participants' balance status influenced the energy cost associated with active video game play. DESIGN: Cross-sectional study. SETTING: University research center. PARTICIPANTS: Community-dwelling adults (N=19) aged 70.7±6.4 years. INTERVENTION: Participants played 9 active video games, each for 5 minutes, in random order. Two games (boxing and bowling) were played in both seated and standing positions. MAIN OUTCOME MEASURES: Energy expenditure was assessed using indirect calorimetry while at rest and during game play. Energy expenditure was expressed in kilojoules per minute and metabolic equivalents (METs). Balance was assessed using the mini-BESTest, the Activities-specific Balance Confidence Scale, and the Timed Up and Go (TUG). RESULTS: Mean ± SD energy expenditure was significantly greater for all game conditions compared with rest (all P≤.01) and ranged from 1.46±.41 METs to 2.97±1.16 METs. There was no significant difference in energy expenditure, activity counts, or perceived exertion between equivalent games played while standing and seated. No significant correlations were observed between energy expenditure or activity counts and balance status. CONCLUSIONS: Active video games provide light-intensity exercise in community-dwelling older people, whether played while seated or standing. People who are unable to stand may derive equivalent benefits from active video games played while seated. Further research is required to determine whether sustained use of active video games alters physical activity levels in community settings for this population.

The right place at the right time: the social contexts of combined alcohol and energy drink use

Aims: Little is known about the social and functional aspects of alcohol mixed with energy drink(AmED) consumption. Using a functional substance use perspective and via the lens of socialidentity theory, this paper aims to explore the role of AmED consumption amongst the milieuof nightlife and party culture. Methods: Twenty-five regular AmED consumers aged 18–33participated in semi-structured interviews. Qualitative thematic analysis of transcripts wasundertaken, with a focus on the social contexts and perceived functions of AmED consumption,group dynamics and social identity. Findings: Three main themes were identified: (i) AmED usewas restricted to specific social contexts, (ii) AmED use performed a social function and(iii) AmED users identified with a coherent and consistent social identity. AmED use was almostexclusively reported to occur within group drinking scenarios at parties and licensed venues,particularly nightclubs. AmED users identified with a clear and consistent social identity thatwas distinct from other alcohol consumers, typified by gregarious and extroverted behaviour.AmED use was seen to facilitate these ideals and strengthen group cohesion in appropriatecontexts. Conclusions: Future efforts aiming to elicit changes in AmED consumption practices must account for the fundamental importance of social contexts to AmED use.

Automating performance and energy consumption analysis for cloud applications

In cloud environments, IT solutions are delivered to users via shared infrastructure, enabling cloud service providers to deploy applications as services according to user QoS (Quality of Service) requirements. One consequence of this cloud model is the huge amount of energy consumption and significant carbon footprints caused by large cloud infrastructures. A key and common objective of cloud service providers is thus to develop cloud application deployment and management solutions with minimum energy consumption while guaranteeing performance and other QoS specified in Service Level Agreements (SLAs). However, finding the best deployment configuration that maximises energy efficiency while guaranteeing system performance is an extremely challenging task, which requires the evaluation of system performance and energy consumption under various workloads and deployment configurations. In order to simplify this process we have developed Stress Cloud, an automatic performance and energy consumption analysis tool for cloud applications in real-world cloud environments. Stress Cloud supports the modelling of realistic cloud application workloads, the automatic generation of load tests, and the profiling of system performance and energy consumption. We demonstrate the utility of Stress Cloud by analysing the performance and energy consumption of a cloud application under a broad range of different deployment configurations.

Stress, dopamine, inflammation and energy regulation: Examining the nature of antidepressant-resistance and response

This thesis investigated the nature of treatment-resistant depression and novel antidepressants utilizing a preclinical model of antidepressant-resistance. Chronic disruption of the stress response impaired response to antidepressants and altered dopamine signaling in this model. Inflammatory profile and energy regulation were identified as potential biomarkers for response to ketamine and lithium.

Mining and energy law

This text is an ideal starting point to understand the regulatory regimes and policy challenges relevant to Australia's mining sector.

Lapsed prospecting rights : "the custodian giveth and the custodian taketh away"? Palala Resources (Pty) Ltd v Minister of Mineral Resources and Energy

The decision in Palala Resources (Pty) Ltd v Minister of Mineral Resources and Energy & others 2014 (6) SA 403 (GP) (‘Palala Resources’) brings clarity about the lapsing of a company’s prospecting right in terms of s 56(c) of the Mineral and Petroleum Resources Development Act 28 of 2002 (‘the MPRDA’) upon deregistration of the company, and highlights some of the features of a statutory prospecting right. Section 56(c) determines that a company’s prospecting right will lapse upon deregistration of the company if no prior application has been made, in terms of s 11(1) of the MPRDA, to the Director-General of the Department of Mineral Resources for consent to alienate or transfer the right (item 1 of the Ministerial delegation of 12 May 2004). The principles underlying the decision could also be applied to mining rights granted in terms of the MPRDA. By way of introduction, these rights are briefly sketched before the decision will be set out and discussed. It will be argued that the case shows that despite the public law nature of the MPRDA, there is the need for a proper private-law analysis of these statutory rights.

Social contexts and harms of combined alcohol and energy drink use.

This thesis explores the social contexts and harms of combined alcohol and energy drink use. Findings show that these drinks are exclusively a social drink, are consumed in social groups, and are associated with heavier binge drinking sessions and celebrations. Consumers report being driven by intoxication modification and hedonistic motives. Consumers also report increased rates of many side effects, including cardiac issues and symptoms of anxiety and stress.

CAE crash analysis of structures in oblique loading

This work focussed on how tubular steel structures similar to that in frontal car frames deform under crash conditions. The novelty comes from finding three crash modes: axial crush, transitional and global bending. Each mode was categorised by reaction force and energy absorption, this allowing for better structural design practices.

Energy absorption and crushing behaviour of foam-filled aluminium tubes

The crushing behaviour and energy absorption of foam filled aluminium tubular structures were investigated using the quasi-static compressive tests. The crushing behaviour of the tubular structures changed due to foam filling. The energy absorption of the foam filled tubular structures was improved significantly. Foam filling caused an interaction effect between the tube and the foam during progressive crushing, leading to an increase in the mean crushing load compared to that of the foam or tube itself. This interaction effect might be affected by several parameters such as the density of the foam, the properties of both the foam material and tube material, and the thickness and outer diameter of the tube. In particular, the interaction effect essentially depended on the ratio of the mean crushing force of the foam to that of the tube.

The effect of exercise and nutrition on the mechanostat

In this review, we discuss the effect of increased and decreased loading and nutrition deficiency on muscle and bone mass and strength (and bone length and architecture) independently and combined. Both exercise and nutrition are integral components of the mechanostat model but both have distinctly different roles. Mechanical strain imparted by muscle action is responsible for the development of the external size and shape of the bone and subsequently the bone strength. In contrast, immobilization during growth results in reduced growth in bone length and a loss of bone strength due to large losses in bone mass (a result of endosteal resorption in cortical bone and trabecular thinning) and changes in geometry (bone shafts do not develop their characteristic shape but rather develop a rounded default shape). The use of surrogate measures for peak muscle forces acting on bone (muscle strength, size, or mass) limits our ability to confirm a cause-and-effect relationship between peak muscle force acting on bone and changes in bone strength. However, the examples presented in this review support the notion that under adequate nutrition, exercise has the potential to increase peak muscle forces acting on bone and thus can lead to a proportional increase in bone strength. In contrast, nutrition alone does not influence muscle or bone in a dose-dependent manner. Muscle and bone are only influenced when there is nutritional deficiency – and in this case the effect is profound. Similar to immobilization, the immediate effect of malnutrition is a reduction in longitudinal growth. More specifically, protein and energy malnutrition results in massive bone loss due to endosteal resorption in cortical bone and trabecular thinning. Unlike loading however, there is indirect evidence that severe malnutrition when associated with menstrual dysfunction can shift the mechanostat set point upward, thus leading to less bone accrual for a given amount of bone strain.

Genetic albation of the c-Cbl ubiquitin ligase domain results in increased energy expenditure and improved insulin action

Casitas b-lineage lymphoma (c-Cbl) is a multiadaptor protein with E3-ubiquitin ligase activity residing within its RING finger domain. We have previously reported that c-Cbl–deficient mice exhibit elevated energy expenditure, reduced adiposity, and improved insulin action. In this study, we examined mice expressing c-Cbl protein with a loss-of-function mutation within the RING finger domain (c-Cbl^A/– mice). Compared with control animals, c-Cbl^A/– mice display a phenotype that includes reduced adiposity, despite greater food intake; reduced circulating insulin, leptin, and triglyceride levels; and improved glucose tolerance. c-Cbl^A/– mice also display elevated oxygen consumption (13%) and are protected against high-fat diet–induced obesity and insulin resistance. Unlike c-Cbl^A/– mice, mice expressing a mutant c-Cbl with the phosphatidylinositol (PI) 3-kinase binding domain ablated (c-Cbl^F/F mice) exhibited an insulin sensitivity, body composition, and energy expenditure similar to that of wild-type animals. These results indicate that c-Cbl ubiquitin ligase activity, but not c-Cbl–dependent activation of PI 3-kinase, plays a key role in the regulation of whole-body energy metabolism.

Identifying the energy gap: magnitude and determinants of 5-year weight gain in midage women

Objective: The aims of this study were to estimate average yearly weight gain in midage women and to identify the determinants of weight gain and gaining weight at double the average rate.
Research Methods and Procedures: The study sample comprised 8071 participants (45 to 55 years old) in the Australian Longitudinal Study on Women's Health who completed mailed surveys in 1996, 1998, and 2001.
Results: On average, the women gained almost 0.5 kg per year [average 2.42 kg (95% confidence interval, 2.29 to 2.54) over 5 years]. In multivariate analyses, variables associated with energy balance (physical activity, sitting time, and energy intake), as well as quitting smoking, menopause/hysterectomy, and baseline BMI category were significantly associated with weight gain, but other behavioral and demographic characteristics were not. After adjustment for all of the other biological and behavioral variables, the odds of gaining weight at about twice the average rate (>5 kg over 5 years) were highest for women who quit smoking (odds ratio = 2.94; 95% confidence interval, 2.17, 3.96). There were also independent relationships between the odds of gaining >5 kg and lower levels of habitual physical activity, more time spent sitting, energy intake (but only in women with BMI > 25 at baseline), menopause transition, and hysterectomy.
Discussion: The average weight gain equates with an energy imbalance of only about 10 kcal or 40 kJ per day, which suggests that small sustained changes in the modifiable behavioral variables could prevent further weight gain.

Energy use and thermal comfort in a rammed earth office building

A two-storey rammed earth building was built on the Thurgoona Campus of Charles Sturt University in Albury-Wodonga, Australia, in 1999. The building is novel both in the use of materials and equipment for heating and cooling. The climate at Wodonga can be characterised as hot and dry, so the challenge of providing comfortable working conditions with minimal energy consumption is considerable. This paper describes an evaluation of the building in terms of measured thermal comfort and energy use. Measurements, confirmed by a staff questionnaire, found the building was too hot in summer and too cold in winter. Comparison with another office building in the same location found that the rammed earth building used more energy for heating. The thermal performance of three offices in the rammed earth building was investigated further using simulation to predict office temperatures. Comparisons were made with measurements made over typical weeks in summer and winter. The validated model has been used to investigate key building parameters and strategies to improve the thermal comfort and reduce energy consumption in the building. Simulations showed that improvements could be made by design and control strategy changes.

Energy consumption and real GDP in G7 countries : new evidence from panel cointegration with structural breaks

This paper examines the relationship between capital formation, energy consumption and real GDP in a panel of G7 countries using panel unit root, panel cointegration, Granger causality and long-run structural estimation. We find that capital formation, energy consumption and real GDP are cointegrated and that capital formation and energy consumption Granger cause real GDP positively in the long run. We find that a 1% increase in energy consumption increases real GDP by 0.12–0.39%, while a 1% increase in capital formation increases real GDP by 0.1–0.28%.