Direct evaluation of IEC 61850-9-2 process bus network performance

This letter presents a technique to assess the overall network performance of sampled value process buses based on IEC 61850-9-2 using measurements from a single location in the network. The method is based upon the use of Ethernet cards with externally synchronized time stamping, and characteristics of the process bus protocol. The application and utility of the method is demonstrated by measuring latency introduced by Ethernet switches. Network latency can be measured from a single set of captures, rather than comparing source and destination captures. Absolute latency measures will greatly assist the design testing, commissioning and maintenance of these critical data networks.

Experimental studies of wireless communication and GNSS kinematic positioning performance in high-mobility vehicle environments

In order to support intelligent transportation system (ITS) road safety applications such as collision avoidance, lane departure warnings and lane keeping, Global Navigation Satellite Systems (GNSS) based vehicle positioning system has to provide lane-level (0.5 to 1 m) or even in-lane-level (0.1 to 0.3 m) accurate and reliable positioning information to vehicle users. However, current vehicle navigation systems equipped with a single frequency GPS receiver can only provide road-level accuracy at 5-10 meters. The positioning accuracy can be improved to sub-meter or higher with the augmented GNSS techniques such as Real Time Kinematic (RTK) and Precise Point Positioning (PPP) which have been traditionally used in land surveying and or in slowly moving environment. In these techniques, GNSS corrections data generated from a local or regional or global network of GNSS ground stations are broadcast to the users via various communication data links, mostly 3G cellular networks and communication satellites. This research aimed to investigate the precise positioning system performances when operating in the high mobility environments. This involves evaluation of the performances of both RTK and PPP techniques using: i) the state-of-art dual frequency GPS receiver; and ii) low-cost single frequency GNSS receiver. Additionally, this research evaluates the effectiveness of several operational strategies in reducing the load on data communication networks due to correction data transmission, which may be problematic for the future wide-area ITS services deployment. These strategies include the use of different data transmission protocols, different correction data format standards, and correction data transmission at the less-frequent interval. A series of field experiments were designed and conducted for each research task. Firstly, the performances of RTK and PPP techniques were evaluated in both static and kinematic (highway with speed exceed 80km) experiments. RTK solutions achieved the RMS precision of 0.09 to 0.2 meter accuracy in static and 0.2 to 0.3 meter in kinematic tests, while PPP reported 0.5 to 1.5 meters in static and 1 to 1.8 meter in kinematic tests by using the RTKlib software. These RMS precision values could be further improved if the better RTK and PPP algorithms are adopted. The tests results also showed that RTK may be more suitable in the lane-level accuracy vehicle positioning. The professional grade (dual frequency) and mass-market grade (single frequency) GNSS receivers were tested for their performance using RTK in static and kinematic modes. The analysis has shown that mass-market grade receivers provide the good solution continuity, although the overall positioning accuracy is worse than the professional grade receivers. In an attempt to reduce the load on data communication network, we firstly evaluate the use of different correction data format standards, namely RTCM version 2.x and RTCM version 3.0 format. A 24 hours transmission test was conducted to compare the network throughput. The results have shown that 66% of network throughput reduction can be achieved by using the newer RTCM version 3.0, comparing to the older RTCM version 2.x format. Secondly, experiments were conducted to examine the use of two data transmission protocols, TCP and UDP, for correction data transmission through the Telstra 3G cellular network. The performance of each transmission method was analysed in terms of packet transmission latency, packet dropout, packet throughput, packet retransmission rate etc. The overall network throughput and latency of UDP data transmission are 76.5% and 83.6% of TCP data transmission, while the overall accuracy of positioning solutions remains in the same level. Additionally, due to the nature of UDP transmission, it is also found that 0.17% of UDP packets were lost during the kinematic tests, but this loss doesn't lead to significant reduction of the quality of positioning results. The experimental results from the static and the kinematic field tests have also shown that the mobile network communication may be blocked for a couple of seconds, but the positioning solutions can be kept at the required accuracy level by setting of the Age of Differential. Finally, we investigate the effects of using less-frequent correction data (transmitted at 1, 5, 10, 15, 20, 30 and 60 seconds interval) on the precise positioning system. As the time interval increasing, the percentage of ambiguity fixed solutions gradually decreases, while the positioning error increases from 0.1 to 0.5 meter. The results showed the position accuracy could still be kept at the in-lane-level (0.1 to 0.3 m) when using up to 20 seconds interval correction data transmission.

Employee perceptions of reputation : an ethnographic study

The ability of organizational members to identify and analyse stakeholder opinion is critical to the management of corporate reputation. In spite of the significance of these abilities to corporate reputation management, there has been little effort to document and describe internal organizational influences on such capacities. This ethnographic study conducted in Red Cross Queensland explores how cultural knowledge structures derived from shared values and assumptions among organizational members influence their conceptualisations of organizational reputation. Specifically, this study explores how a central attribute of organizational culture – the property of cultural selection – influences perceptions of organizational reputation held by organizational members. We argue that these perceptions are the result of collective processes that synthesise (with varying degrees of consensus) member conceptualisations, interpretations, and representations of environmental realities in which their organization operates. Findings and implications for organizational action suggest that while external indicators of organizational reputation are acknowledged by members as significant, the internal influence of organizational culture is a far stronger influence on organizational action.

The pomegranate cycle : reconfiguring opera through performance, technology & composition

The Pomegranate Cycle is a practice-led enquiry consisting of a creative work and an exegesis. This project investigates the potential of self-directed, technologically mediated composition as a means of reconfiguring gender stereotypes within the operatic tradition. This practice confronts two primary stereotypes: the positioning of female performing bodies within narratives of violence and the absence of women from authorial roles that construct and regulate the operatic tradition. The Pomegranate Cycle redresses these stereotypes by presenting a new narrative trajectory of healing for its central character, and by placing the singer inside the role of composer and producer. During the twentieth and early twenty-first century, operatic and classical music institutions have resisted incorporating works of living composers into their repertory. Consequently, the canon’s historic representations of gender remain unchallenged. Historically and contemporarily, men have almost exclusively occupied the roles of composer, conductor, director and critic, and therefore men have regulated the pedagogy, performance practices, repertoire and organisations that sustain classical music. In this landscape, women are singers, and few have the means to challenge the constructions of gender they are asked to reproduce. The Pomegranate Cycle uses recording technologies as the means of driving change because these technologies have already challenged the regulation of the classical tradition by changing people’s modes of accessing, creating and interacting with music. Building on the work of artists including Phillips and van Veen, Robert Ashley and Diamanda Galas, The Pomegranate Cycle seeks to broaden the definition of what opera can be. This work examines the ways in which the operatic tradition can be hybridised with contemporary musical forms such as ambient electronica, glitch, spoken word and concrete sounds as a way of bringing the form into dialogue with contemporary music cultures. The ultilisation of other sound cultures within the context of opera enables women’s voices and stories to be presented in new ways, while also providing a point of friction with opera’s traditional storytelling devices. The Pomegranate Cycle simulates aesthetics associated with Western art music genres by drawing on contemporary recording techniques, virtual instruments and sound-processing plug-ins. Through such simulations, the work disrupts the way virtuosic human craft has been used to generate authenticity and regulate access to the institutions that protect and produce Western art music. The DIY approach to production, recording, composition and performance of The Pomegranate Cycle demonstrates that an opera can be realised by a single person. Access to the broader institutions which regulate the tradition are not necessary. In short, The Pomegranate Cycle establishes that a singer can be more than a voice and a performing body. She can be her own multimedia storyteller. Her audience can be anywhere.

Performance characteristics of compound curved sandwich shell structures

Sandwich shells have recently emerged as aesthetically pleasing, efficient and economical structural systems, with a number of applications. They combine the advantages of sandwich layer technology together with those of shell action. With different materials and thicknesses used in the sandwich layers, their performance characteristics largely remain un-quantified and there are no guidelines at present for their design. This research paper provides verification, through finite element modeling and testing, for the application of this technology to dome styled dwellings with research currently being conducted into the further application to roofing and floor structures.

Re-examining the evidence in radiation dermatitis management literature : an overview and a critical appraisal of systematic reviews

Purpose: To provide an overview and a critical appraisal of systematic reviews (SRs) of published interventions for the prevention/management of radiation dermatitis. Methods and Materials: We searched Medline, CINAHL, Embase, and the Cochrane Library. We also manually searched through individual reference lists of potentially eligible articles and a number of key journals in the topic area. Two authors screened all potential articles and included eligible SRs. Two authors critically appraised and extracted key findings from the included reviews using AMSTAR (the measurement tool for “assessment of multiple systematic reviews”). Results: Of 1837 potential titles, 6 SRs were included. A number of interventions have been reported to be potentially beneficial for managing radiation dermatitis. Interventions evaluated in these reviews included skin care advice, steroidal/nonsteroidal topical agents, systemic therapies, modes of radiation delivery, and dressings. However, all the included SRs reported that there is insufficient evidence supporting any single effective intervention. The methodological quality of the included studies varied, and methodological shortfalls in these reviews might create biases to the overall results or recommendations for clinical practice. Conclusions: An up-to-date high-quality SR in the prevention/management of radiation dermatitis is needed to guide practice and direction for future research. We recommend that clinicians or guideline developers critically evaluate the information of SRs in their decision making.

Empirical IEEE 802.11p performance evaluation on test tracks

IEEE 802.11p is the new standard for inter-vehicular communications (IVC) using the 5.9 GHz frequency band; it is planned to be widely deployed to enable cooperative systems. 802.11p uses and performance have been studied theoretically and in simulations over the past years. Unfortunately, many of these results have not been confirmed by on-tracks experimentation. In this paper, we describe field trials of 802.11p technology with our test vehicles. Metrics such as maximum range, latency and frame loss are examined.

Clinical performance of a new silicone hydrogel contact lens over 6 months of extended wear

Purpose: Silicone hydrogel contact lenses (CLs) are becoming increasingly popular for daily wear (DW), extended wear (EW) and continuous wear (CW), due to their higher oxygen transmissibility compared to hydrogel CLs. The aim of this study was to investigate the clinical and subjective performance of asmofilcon A (Menicon Co., Ltd), a new surface treated silicone hydrogel CL, during 6-night EW over 6 months (M). Methods: A prospective, randomised, single-masked, monadic study was conducted. N=60 experienced DW soft CL wearers were randomly assigned to wear either asmofilcon A (test: Dk=129, water content (WC)=40%, Nanogloss surface treatment) or senofilcon A (control: Dk=103, WC=38%, PVP internal wetting agent, Vistakon, Johnson & Johnson Vision Care) CLs bilaterally for 6 M on an EW basis. A PHMB-preserved solution (Menicon Co., Ltd) was dispensed for CL care. Evaluations were conducted at CL delivery and after 1 week (W), 4 W, 3 M and 6 M of EW. At each visit, a range of objective and subjective clinical performance measures were assessed. Results: N=50 subjects (83%) successfully completed the study, with the majority of discontinuations due to loss to follow-up (n=3) or moving away/travel (n=5). N=2 subjects experienced adverse events; n=1 unilateral red eye with asmofilcon A and n=1 asymptomatic infiltrate with senofilcon A. There were no significant differences in high or low contrast distance visual acuity (HCDVA or LCDVA) between asmofilcon A and senofilcon A; however, LCDVA decreased significantly over time with both CL types (p<0.05). The two CL types did not vary significantly with respect to any of the objective and subjective measures assessed (p>0.05); CL fitting characteristics and CL surface measurements were very similar and mean bulbar and limbal redness measures were always less than grade 1.0. Superior palpebral conjunctival injection showed a statistically, but not clinically, significant increase over time with both CL types (p<0.05). Corneal staining did not vary significantly between asmofilcon A and senofilcon A (p>0.05), with low median gradings of less than 0.5 observed for all areas assessed. There were no solution-related staining reactions observed with either CL type. The asmofilcon A and senofilcon A CLs were both rated highly with respect to overall comfort, with medians of 14 or 15 hours of comfortable lens wearing time per day reported at each of the study visits (p>0.05). Conclusions: Over 6 months of EW, the asmofilcon A and senofilcon A CLs performed in a similar manner with respect to visual acuity, ocular health and CL performance measures. Some changes over time were observed with both CL types, including reduced LCDVA and increased superior palpebral injection, which warrant further investigation in longer-term EW studies. Asmofilcon A appeared to be equivalent in performance to senofilcon A.

The performance and politics of practice for New Graduate Nurses

The change from nursing student to Registered Nurse (RNs) is both a desirable and anticipated event for New Graduate Nurses (NGNs). Having completed their formal education, most NGNs approach the threshold of their professional career with mixed emotions. While excited about the future and eagerly awaiting the commencement of employment, many are aware that this change also signifies a time of personal upheaval, professional insecurity and further personal learning. In the nursing professions’ enthusiasm to facilitate a smooth passage for NGNs a vast literature now addresses preparation-for-practice degrees, as well as the perceived workplace deficits and support needs of NGNs. However, the importance this change from working as a student to working as a NGN is not well conceptualised, theorised or understood as this largely instrumental literature essentially reduces the problematisation of the NGN transition experience to the problematisation of the individual by identifying NGNs as ‘the’ problem. Subsequently it fails to expose or challenge the normative assumptions underpinning processes that have formerly been considered solutions, or, the impact of such processes in a workplace that frames itself as “supportive”. Conspicuously absent is an exploration of how the NGN role is performed by former students, now beginning RNs undergoing the very personal transition of “becoming registered nurses”. Using Goffman’s (1956) theorisation of performance in everyday life exploring how process and meaning in mundane interactions present themselves in the “regular” lives of people at large, and Margaret Archer’s (2000) work emphasising the significance of the inner dialogue for managing the emotions that emerge out of situations that confront us, this paper draws upon data collected during a study of NGNs’ experience of transition to practice (Malouf 2010). It focuses on an emergent understanding of the need to differentiate the performance of ‘student’ from that of ‘NGN’ role. Further, it explores how these roles have become conflated into a conceptual continuum and viewed as a slide from student to NGN performance, rather than a significant moment of change involving roles that need to be distinctly defined as a necessary precursor to enhancing and supporting the professional and personal development of beginning practitioners.

The Impact of gender identity-conscious HR structures on performance : mediating effects of gender diversity

Gender identity-conscious HR structures signal an organization’s perspective on gender diversity. The signal produces perceptions that the organization values gender diversity leading to a gender diverse workforce. In turn, a gender diverse workforce provides a firm with a competitive advantage which should result in higher performance. This paper tests the mediating effects of gender diversity (at non-management and management levels) in the relationship between gender identity-conscious HR structures and performance. The findings indicate that non-management gender diversity partially mediates the relationship between HR structures and productivity, and management gender diversity partially mediates the relationship between HR structures and perceived market performance.

Threat appraisal for harm from falls: Insights for development of education-based intervention

Objective: This study aims to describe how patients perceive the threat of falls in hospitals, to identify patient characteristics that are associated with greater or lesser perceptions of the threat of falls, and to examine whether there is a discord between the risk that patients perceive in general and the risk that they perceive for themselves personally. Method: A cross-sectional survey amongst geriatric rehabilitation inpatients in Brisbane, Australia, was implemented. The first component of the survey dealt with the ‘general’ nature of in-hospital falls and falls related risks while the second component of the survey was directed at identifying whether the patient held the same belief for themselves. Results: A total of 21 out of 125 participants (17%) indicated that they felt that they were at risk of falling during their hospitalisation and 28 (22%) felt that they would injure themselves if they were to fall. Self-perceived risk of falls was associated with decreasing age and lower cognitive function (Functional Independence Measure Cognitive score). A majority of patients felt that falls most commonly occur in the bathroom [n=67 (54%)] and that if they were to fall, they would fall in the bathroom [n=56 (45%)]. Discussion: Patients generally do not think they are at risk of falling while in hospital and this may contribute to poor adherence to falls prevention strategies. It is possible that raising patient perception of the risk of falls and injury from falls in hospitals may help improve adherence to falls prevention strategies in this setting.