936 resultados para performance assessment


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The non-destructive evaluation of the water permeability of concrete structures is a long standing challenge, principally due to the difficulty of achieving a uni-direction flow for computing the water permeability coefficient. The use of a guard ring (GR) was originally proposed for the in situ sorptivity test, but little information can be found for the water permeability test. In this study, the effect of a GR was carefully examined through the flow simulation, which was verified by carrying out experiments. It was observed that the GR can confine the flow near the surface, but cannot achieve a uni-directional flow across the whole depth of flow. To achieve a better performance, it is essential to consider the effects of the size of the inner seal and the GR and the significant interaction between these two. The analysis of the experimental data has indicated that the GR influences the flow for porous concretes, but there is no significant effect for dense concretes. Further investigation, validated using the flow-net theory, has shown a strong correlation between the water permeability coefficients obtained with the GR (K w-GR) and without it (K w-No GR), suggesting that one dimensional flow is not essential for interpreting data for site tests. Another practical issue was that more than 30 % of the tests with GR failed due to the difficulty of achieving a good seal between the inner and the outer chambers. Based on the work reported in this paper, a new water permeability test is proposed.

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The work aims at assessing the success of Brunetta’s reform (Legislative Decree n. 150/2009), a far-reaching reform that aimed at improving both organizational and individual performance in Italian public administration through a specific planning and control process (the performance cycle) and most of all through two new tools, Performance Plan and Performance Report. The success of the reform is assessed, with particular emphasis on local governments, analyzing the diffusion and use of these new tools. The study has been conducted using a deductive-inductive methodology. Thus, after a study of managerial reforms in Italy and performance measurement literature, a possible model (PerformEL Model) local governments could follow to draw up Performance Plan and Report as effective tools for performance measurement has been designed (deductive phase). Performance Plans 2011-2013 and Performance Report 2011 downloaded from Italian big sized municipalities’ websites have been analyzed in the light of PerformEL Model, to assess the diffusion of the documents and their coherence with legal requirements and suggestions from literature (inductive phase). Data arising from the empirical analysis have been studied to evaluate the diffusion and the effectiveness of big sized municipalities’ Performance Plans and Reports as performance measurement tools and thus to assess the success of the reform (feedback phase). The study shows a scarce diffusion of the documents; they are mostly drew up because of their compulsoriness or to gain legitimization. The results testify the failure of Brunetta’s reform, at least with regard to local governments.

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Sports supplements are becoming a regular dietary addition for consumers who view such products as a means of improving their health and performance. Previously estrogenic endocrine disruptors (EDs) were detected in 80% of 116 sports supplements investigated by biological in vitro reporter gene assays (RGAs). The aim of this study was to quantify the hormonal activity in 50 of these sports supplement samples using a validated estrogen RGA and perform an exposure and risk assessment for human health. Results showed that 17β-estradiol equivalent levels were higher than those reported as being present in the typical human omnivore diet in 33 of the sports supplements and higher than the acceptable daily intake (ADI) in 13 of these products. The highest activity samples presented a potential to influence the human daily exposure to 17β-estradiol like activity in various risk groups with a predicted hormonal impact of greatest concern in young boys and postmenopausal women. In conclusion, consumers of sports supplements may be exposed to high levels of estrogenic EDs.

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Overwintering diving ducks at Lough Neagh have declined dramatically in recent years, but it has been suggested that on-to-offshore redistribution may have led to an underestimate of numbers. Most species feed nocturnally and their distribution at night is unknown. We used radar and visual observations from on board commercial sand barges to determine the diurnal distribution of diving duck flocks in an effort to assess the feasibility of using standard
boat-mounted radar to describe their nocturnal feeding distribution. Sand barge radar was poor in identifying flocks compared to independent visual observations as it was sensitive to interference by waves during windy conditions. However, visual observations were useful in describing diurnal distribution. Sand barges were on average 1.5km from shore when a flock of diving ducks was observed and the probability of detection declined with distance from shore. This supports the reliability of shore-based counts in monitoring and surveillance. Given the poor performance of commercially available boatmounted radar systems, we recommend the use of specialised terrestrial Bird Detecting Radar to determine the movements of diving ducks at Lough Neagh.

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This chapter presents an overview on several performance-based approaches for concrete durability specification and conformity assessment of the as-built structure.

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Statistical downscaling (SD) methods have become a popular, low-cost and accessible means of bridging the gap between the coarse spatial resolution at which climate models output climate scenarios and the finer spatial scale at which impact modellers require these scenarios, with various different SD techniques used for a wide range of applications across the world. This paper compares the Generator for Point Climate Change (GPCC) model and the Statistical DownScaling Model (SDSM)—two contrasting SD methods—in terms of their ability to generate precipitation series under non-stationary conditions across ten contrasting global climates. The mean, maximum and a selection of distribution statistics as well as the cumulative frequencies of dry and wet spells for four different temporal resolutions were compared between the models and the observed series for a validation period. Results indicate that both methods can generate daily precipitation series that generally closely mirror observed series for a wide range of non-stationary climates. However, GPCC tends to overestimate higher precipitation amounts, whilst SDSM tends to underestimate these. This infers that GPCC is more likely to overestimate the effects of precipitation on a given impact sector, whilst SDSM is likely to underestimate the effects. GPCC performs better than SDSM in reproducing wet and dry day frequency, which is a key advantage for many impact sectors. Overall, the mixed performance of the two methods illustrates the importance of users performing a thorough validation in order to determine the influence of simulated precipitation on their chosen impact sector.

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The efficiency of generation plants is an important measure for evaluating the operating performance. The objective of this paper is to evaluate electricity power generation by conducting an All-Island-Generator-Efficiency-Study (AIGES) for the Republic of Ireland and Northern Ireland by utilising a Data Envelopment Analysis (DEA) approach. An operational performance efficiency index is defined and pursued for the year 2008. The economic activities of electricity generation units/plants examined in this paper are characterized by numerous input and output indicators. Constant returns to scale (CRS) and variable returns to scale (VRS) type DEA models are employed in the analysis. Also a slacks based analysis indicates the level of inefficiency for each variable examined. The findings from this study provide a general ranking and evaluation but also facilitate various interesting efficiency comparisons between generators by fuel type.

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It is acknowledged that one of the consequences of the ageing process is cognitive decline, which leads to an increase in the incidence of illnesses such as dementia. This has become ever more relevant due to the projected increase in the ageing demographic. Dementia affects visuo-spatial perception, causing difficulty with wayfinding, even during the early stages of the disease. The literature widely recognises the physical environment’s role in alleviating symptoms of dementia and improving quality of life for residents. It also identifies the lack of available housing options for older people with dementia and consequently the current stock is ill-equipped to provide adequate support.
Recent statistics indicate that 80% of those residing in nursing or residential care homes have some form of dementia or severe memory problems. The shift towards institutional care settings, the need for specialist support and care, places a greater impetus on the need for a person-centred approach to tackle issues related to wayfinding and dementia.
This thesis therefore aims to improve design for dementia in nursing and residential care settings in the context of Northern Ireland. This will be undertaken in order to provide a better understanding of how people with dementia experience the physical environment and to highlight features of the design that assist with wayfinding. Currently there are limited guidelines on design for dementia, meaning that many of these are theoretical, anecdotal and not definitive. Hence a greater verification to address the less recognised design issues is required. This is intended to ultimately improve quality of life, wellbeing, independence and uphold the dignity of people with dementia living in nursing or residential care homes.
The research design uses a mixed methods approach. A thorough preparation and consideration of ethical issues informed the methodology. The various facets were also trialled and piloted to identify any ethical, technological, methodological, data collection and analysis issues. The protocol was then amended to improve or resolve any of the aforementioned issues. Initially a questionnaire based on leading design recommendations was conducted with home managers. Semi-structured interviews were developed from this and conducted with staff and resident’s next of kin. An evidence-based approach was used to design a study which used ethnographic methods, including a wayfinding task. This followed a repeated measures design which would be used to actively engage residents with dementia in the research. Complementary to the wayfinding task, conversational and semi-structured interviews were used to promote dialogue and direct responses with the person with dementia. In addition to this, Space Syntax methodologies were used to examine the physical properties of the architectural layout. This was then cross-examined with interview responses and data from the wayfinding tasks.
A number of plan typologies were identified and were determined as synonymous with decision point types which needed to be made during the walks. The empirical work enabled the synthesis of environmental features which support wayfinding.
Results indicate that particular environmental features are associated with improved performance on the wayfinding tasks. By enhancing design for dementia, through identifying the attributes, challenges with wayfinding may be overcome and the benefits of the physical environment can be seen to promote wellbeing.
The implications of this work mean that the environmental features which have been highlighted from the project can be used to inform guidelines, thus adding to existing knowledge. Future work would involve the dissemination of this information and the potential for it to be made into design standards or regulations which champion design for dementia. These would increase awareness for designers and stakeholders undertaking new projects, extensions or refurbishments.
A person-centred, evidence-based design was emphasised throughout the project which guaranteed an in-depth study. There were limitations due to the available resources, time and funding. Future research would involve testing the identified environmental features within a specific environment to enable measured observation of improvements.

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Background: Serious case reviews and research studies have indicated weaknesses in risk assessments conducted by child protection social workers. Social workers are adept at gathering information but struggle with analysis and assessment of risk. The Department for Education wants to know if the use of a structured decision-making tool can improve child protection assessments of risk.

Methods/design: This multi-site, cluster-randomised trial will assess the effectiveness of the Safeguarding Children Assessment and Analysis Framework (SAAF). This structured decision-making tool aims to improve social workers' assessments of harm, of future risk and parents' capacity to change. The comparison is management as usual.

Inclusion criteria: Children's Services Departments (CSDs) in England willing to make relevant teams available to be randomised, and willing to meet the trial's training and data collection requirements.

Exclusion criteria: CSDs where there were concerns about performance; where a major organisational restructuring was planned or under way; or where other risk assessment tools were in use.

Six CSDs are participating in this study. Social workers in the experimental arm will receive 2 days training in SAAF together with a range of support materials, and access to limited telephone consultation post-training. The primary outcome is child maltreatment. This will be assessed using data collected nationally on two key performance indicators: the first is the number of children in a year who have been subject to a second Child Protection Plan (CPP); the second is the number of re-referrals of children because of related concerns about maltreatment. Secondary outcomes are: i) the quality of assessments judged against a schedule of quality criteria and ii) the relationship between the three assessments required by the structured decision-making tool (level of harm, risk of (re) abuse and prospects for successful intervention).

Discussion: This is the first study to examine the effectiveness of SAAF. It will contribute to a very limited literature on the contribution that structured decision-making tools can make to improving risk assessment and case planning in child protection and on what is involved in their effective implementation.

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We present a rigorous methodology and new metrics for fair comparison of server and microserver platforms. Deploying our methodology and metrics, we compare a microserver with ARM cores against two servers with ×86 cores running the same real-time financial analytics workload. We define workload-specific but platform-independent performance metrics for platform comparison, targeting both datacenter operators and end users. Our methodology establishes that a server based on the Xeon Phi co-processor delivers the highest performance and energy efficiency. However, by scaling out energy-efficient microservers, we achieve competitive or better energy efficiency than a power-equivalent server with two Sandy Bridge sockets, despite the microserver's slower cores. Using a new iso-QoS metric, we find that the ARM microserver scales enough to meet market throughput demand, that is, a 100% QoS in terms of timely option pricing, with as little as 55% of the energy consumed by the Sandy Bridge server.

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Automotive manufacturers require improved part load engine performance to further improve fuel economy. For a swing vane VGS (Variable Geometry Stator) turbine this means a more closed stator vane, to deal with the low MFRs (Mass Flow Rates), high PRs (Pressure Ratios) and low rotor rotational speeds. During these conditions the turbine is operating at low velocity ratios. As more energy is available at high pressure ratios and during lower turbocharger rotational speeds, a turbine which is efficient at these conditions is desirable. Another key aspect for automotive manufacturers is engine responsiveness. High inertia designs result in “turbo lag” which means an increased time before the target boost pressure is reached. Therefore, designs with improved performance at low velocity ratios, reduced inertia or an increased swallowing capacity are the current targets for turbocharger manufacturers.

To try to meet these design targets a CFD (Computational Fluid Dynamics) study was performed on a turbine wheel using splitter blades. A number of parameters were investigated. These included splitter blade merdional length, blade number and blade angle distribution.

The numerical study was performed on a scaled automotive VGS. Three different stator vane positions have been analysed. A single passage CFD model was developed and used to provide information on the flow features affecting performance in both the stator vanes and turbine.

Following the CFD investigation the design with the best compromise in terms of performance, inertia and increased MFP (Mass Flow Parameter) was selected for manufacture and testing. Tests were performed on a scaled, low temperature turbine test rig. The aerodynamic flow path of the gas stand was the same as that investigated during the CFD. The test results revealed a design which had similar performance at the closed stator vane positions when compared to the baseline wheel. At the maximum MFR stator vane condition a drop of −0.6% pts in efficiency was seen. However, 5.5% increase in MFP was obtained with the additional benefit of a drop in rotor inertia of 3.7%, compared to the baseline wheel.

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Double Skin Façades (DSFs) are becoming increasingly popular architecture for commercial office buildings. Although DSFs are widely accepted to have the capacity to offer significant passive benefits and enable low energy building performance, there remains a paucity of knowledge with regard to their operation. Identification of the most determinant architectural parameters of DSFs is the focus of ongoing research. This paper presents an experimental and simulation study of a DSF installed on a commercial building in Dublin, Ireland. The DSF is south facing and acts to buffer the building from winter heat losses, but risks enhancing over-heating on sunny days. The façade is extensively monitored during winter months. Computational Fluid Dynamic (CFD) models are used to simulate the convective operation of the DSF. This research concludes DSFs as suited for passive, low energy architecture in temperature climates such as Ireland but identifies issues requiring attention in DSF design.

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An efficient and robust case sorting algorithm based on Extended Equal Area Criterion (EEAC) is proposed in this paper for power system transient stability assessment (TSA). The time-varying degree of an equivalent image system can be deduced by comparing the analysis results of Static EEAC (SEEAC) and Dynamic EEAC (DEEAC), the former of which neglects all time-varying factors while the latter partially considers the time-varying factors. Case sorting rules according to their transient stability severity are set combining the time-varying degree and fault messages. Then a case sorting algorithm is designed with the “OR” logic among multiple rules, based on which each case can be identified into one of the following five categories, namely stable, suspected stable, marginal, suspected unstable and unstable. The performance of this algorithm is verified by studying 1652 contingency cases from 9 real Chinese provincial power systems under various operating conditions. It is shown that desirable classification accuracy can be achieved for all the contingency cases at the cost of very little extra computational burden and only 9.81% of the whole cases need to carry out further detailed calculation in rigorous on-line TSA conditions.

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This paper reports on the accuracy of new test methods developed to measure the air and water permeability of high-performance concretes (HPCs). Five representative HPC and one normal concrete (NC) mixtures were tested to estimate both repeatability and reliability of the proposed methods. Repeatability acceptance was adjudged using values of signal-noise ratio (SNR) and discrimination ratio (DR), and reliability was investigated by comparing against standard laboratory-based test methods (i.e., the RILEM gas permeability test and BS EN water penetration test). With SNR and DR values satisfying recommended criteria, it was concluded that test repeatability error has no significant influence on results. In addition, the research confirmed strong positive relationships between the proposed test methods and existing standard permeability assessment techniques. Based on these findings, the proposed test methods show strong potential to become recognized as international methods for determining the permeability of HPCs.