Life cycle cost analysis of silicon and organic building integrated photovoltaic systems (BiPV)

Despite the undisputed benefits associated with photovoltaic (PV) technology, the financial barrier acts as the major hurdle before it is seen as a commercial competitive form of renewable energy. Many studies have been performed outlining the life cycle energy benefits of PV technology. However, there has been limited number of studies dedicated to the life cycle cost impacts. The aim of this paper is to identify whether life cycle cost analysis is the best approach to determining the cost contributors or savings associated with this technology. This paper has been structured similarly to previous life cycle energy studies to consider the cost implications involved within each area of the products lifecycle. Amongst many new developments, traditional silicon based units have been challenged by the introduction of new organic systems; and recent studies highlight that these systems offer major cost reductions. Based on an analysis of current literature, this paper identifies that the recent growth and development of both organic and silicon based systems have had a considerable effect on the cost of PV cells. The competitive nature of the renewable energy market will also impact on a life cycle cost analysis; and any potential findings will valid for a limited timeframe.

Distance from water, sex and approach direction influence flight distances among habituated black swans

In many animals, response to predators occurs at greater distances the further an individual is from a refuge, but this has rarely been investigated in birds. Here, we test the hypothesis that the further from refuge (i.e. water) a foraging black swan Cygnus atratus is situated, the longer its flight initiation distance (FID) in response to a pedestrian approach on land. As predicted, swans situated farther from water exhibited longer FIDs compared with those closer to the shore. In addition, there was the possibility of an interesting interaction effect (p < 0.061) of sex and direction of approach on FID. Whilst males tended to not alter their response in relation to the angle of approach relative to the water, females tended to respond at longer distances, when approached from the shore than when approached from the land or parallel to the shore. This is one of the first reports of sex differences in FIDs for birds, with sex differences only manifesting themselves under certain approach types. Group size, the order of repeated approaches, and time of day did not influence responses, although starting distance of approach was positively related to FID.

An examination of a proposed DSM-IV pathological gambling hierarchy in a treatment seeking population: similarities with substance dependence and evidence for three classification systems

Toce-Gerstein et al. (Addiction 98:1661–1672, 2003) investigated the distribution of Diagnostic and Statistical Manual for Mental Disorders, 4th edition (DSM-IV) pathological gambling criteria endorsement in a U.S. community sample for those people endorsing a least one of the DSM-IV criteria (n = 399). They proposed a hierarchy of gambling disorders where endorsement of 1–2 criteria were deemed ‘At-Risk’, 3–4 ‘Problem gamblers’, 5–7 ‘Low Pathological’, and 8–10 ‘High Pathological’ gamblers. This article examines these claims in a larger Australian treatment seeking population. Data from 4,349 clients attending specialist problem gambling services were assessed for meeting the ten DSM-IV pathological gambling criteria. Results found higher overall criteria endorsement frequencies, three components, a direct relationship between criteria endorsement and gambling severity, clustering of criteria similar to the Toce-Gerstein et al. taxonomy, high accuracy scores for numerical and criteria specific taxonomies, and also high accuracy scores for dichotomous pathological gambling diagnoses. These results suggest significant complexities in the frequencies of criteria reports and relationships between criteria.

Dimensions and metrics for evaluating recommendation systems

Recommendation systems support users and developers of various computer and software systems to overcome information overload, perform information discovery tasks, and approximate computation, among others. They have recently become popular and have attracted a wide variety of application scenarios ranging from business process modeling to source code manipulation. Due to this wide variety of application domains, different approaches and metrics have been adopted for their evaluation. In this chapter, we review a range of evaluation metrics and measures as well as some approaches used for evaluating recommendation systems. The metrics presented in this chapter are grouped under sixteen different dimensions, e.g., correctness, novelty, coverage. We review these metrics according to the dimensions to which they correspond. A brief overview of approaches to comprehensive evaluation using collections of recommendation system dimensions and associated metrics is presented. We also provide suggestions for key future research and practice directions.

The effects of circadian rhythmicity of salivary cortisol and testosterone on maximal isometric force, maximal dynamic force, and power output

The study investigated the effects of circadian rhythm of cortisol (C) and testosterone (T) on maximal force production (Fpeak) and power output (Ppeak). Twenty male university students (mean age = 23.8 ± 3.6 years, height = 177.5 ± 6.4 cm, weight = 78.9 ± 11.2 kg) performed 4 time-of-day testing sessions consisting of countermovement jumps (CMJs), squat jumps (SJ), isometric midthigh pulls (IMTPs), and a 1-repetition maximum (1RM) squat. Saliva samples were collected at 0800, 1200, 1600, and 2000 hours to assess T and C levels on each testing day. Session rate-of-perceived exertion (RPE) scores were collected after each session. The results showed that Fpeak and Ppeak presented a clear circadian rhythm in CMJ and IMTP but not in SJ. One repetition maximum squat did not display a clear circadian rhythm. Session RPE scores collected at 0800 and 2000 hours were significantly (p ≤ 0.05) higher than those obtained at 1200 and 1600 hours. Salivary T and C displayed a clear circadian rhythm with highest values at 0800 hours and lowest at 2000 hours; however, no significant correlation was found between T and C with Fpeak and Ppeak. A very strong correlation was found between Taural with Fpeak of CMJ and IMTP and Ppeak of CMJ (r = 0.86, r = 0.84 and r = 0.8, p ≤ 0.001). The study showed the existence of a circadian rhythm in Fpeak and Ppeak in CMJ and IMTP. The evidence suggests that strength and power training or testing should be scheduled later during the day. The use of Taural seemed to be a more effective indicator of physical performance than hormonal measures, and the use of session RPE should also be closely monitored because it may present a circadian rhythm.

Policy-based SQLIA detection and prevention approach for RFID systems

While SQL injection attacks have been plaguing web application systems for years, the possibility of them affecting RFID systems was only identified very recently. However, very little work exists to mitigate this serious security threat to RFID-enabled enterprise systems. In this paper, we propose a policy-based SQLIA detection and prevention method for RFID systems. The proposed technique creates data validation and sanitization policies during content analysis and enforces those policies during runtime monitoring. We tested all possible types of dynamic queries that may be generated in RFID systems with all possible types of attacks that can be mounted on those systems. We present an analysis and evaluation of the proposed approach to demonstrate the effectiveness of the proposed approach in mitigating SQLIA.