67 resultados para Performance--Ability testing.
Resumo:
Blending insights from the contingency theory, the resource-based view, and the AMO theory, the purpose of this paper is to investigate the HRM-performance causal relationship in the Greek context. The empirical research is based on a sample of 178 organisations operating in the Greek manufacturing sector. Using structural equation modelling the results of the study revealed that the ability to perform (resourcing and development), motivation to perform (compensation and incentives), and opportunity to perform (involvement and job design) HRM policy domains are moderated by business strategies (cost, quality, innovation), and additionally, the motivation to perform is further moderated by managerial style and organisational culture. Further, the results indicate that the impact of HRM policies on organisational performance is fully mediated by employee skills, attitudes, and behaviour. The paper concludes that although the motivation to perform HRM policy domain causes organisational performance, through employee attitudes, it may be supported that organisational performance positively moderates the effectiveness of this HRM policy domain, raising thus the question of reverse causality.
Resumo:
This study examines the selectivity and timing performance of 218 UK investment trusts over the period July 1981 to June 2009. We estimate the Treynor and Mazuy (1966) and Henriksson and Merton (1981) models augmented with the size, value, and momentum factors, either under the OLS method adjusted with the Newey-West procedure or under the GARCH(1,1)-in-mean method following the specification of Glosten et al. (1993; hereafter GJR-GARCH-M). We find that the OLS method provides little evidence in favour of the selectivity and timing ability, consistent with previous studies. Interestingly, the GJR-GARCH-M method reverses this result, showing some relatively strong evidence on favourable selectivity ability, particularly for international funds, as well as favourable timing ability, particularly for domestic funds. We conclude that the GJR-GARCH-M method performs better in evaluating fund performance compared with the OLS method and the non-parametric approach, as it essentially accounts for the time-varying characteristics of factor loadings and hence obtains more reliable results, in particular, when the high frequency data, such as the daily returns, are used in the analysis. Our results are robust to various in-sample and out-of-sample tests and have valuable implications for practitioners in making their asset allocation decisions across different fund styles. © 2012 Elsevier B.V.
Resumo:
This paper reports findings of a two year study concerning the development and implementation of a general-purpose computer-based assessment (CBA) system at a UK University. Data gathering took place over a period of nineteen months, involving a number of formative and summative assessments. Approximately 1,000 students, drawn from undergraduate courses, were involved in the exercise. The techniques used in gathering data included questionnaires, observation, interviews and an analysis of student scores in both conventional examinations and computer-based assessments. Comparisons with conventional assessment methods suggest that the use of CBA techniques may improve the overall performance of students. However it is clear that the technique must not be seen as a "quick fix" for problems such as rising student numbers. If one accepts that current systems test only a relatively narrow range of skills, then the hasty implementation of CBA systems will result in a distorted and inaccurate view of student performance. In turn, this may serve to reduce the overall quality of courses and - ultimately - detract from the student learning experience. On the other hand, if one adopts a considered and methodical approach to computer-based assessment, positive benefits might include increased efficiency and quality, leading to improved student learning.
Resumo:
Aim: To evaluate the performance of an aspheric diffractive multifocal acrylic intraocular lens (IOL), ZMB00 1-Piece Tecnis. Setting: Five sites across Europe. Methods: Fifty-two patients with cataracts (average age 68.5±10.5 years, 35 female) were bilaterally implanted with the aspheric diffractive multifocal IOL after completing a questionnaire regarding their optical visual symptoms, use of visual correction and their visual satisfaction. The questionnaire was completed again 4-6 months after surgery along with measures of uncorrected and best-corrected distance and near visual acuity, under photopic and mesopic lighting, reading ability, defocus curve testing and ocular examination for adverse events. Results: The residual refractive error was 0.01±0.47D with 56% of eyes within ±0.25D and 97% within ±1.0D. Uncorrected visual acuity was 0.02±0.10logMAR at distance and 0.15±0.30 logMAR at near, only reducing to 0.07±0.10logMAR at distance and 0.21±0.25logMAR at near in mesopic conditions.The defocus curve showed a near addition between 2.5-3.0 D allowing a reading acuity of 0.08±0.13 logMAR, with a range of clear vision <0.3 logMAR of ∼4.0 D. The average reading speed was 121.4±30.8 words per minute. Spectacle independence was 100% for distance and 88% for near, with high levels of satisfaction reported. Overall rating of vision without glasses could be explained (r=0.760) by preoperative best-corrected distance acuity, postoperative reading acuity and postoperative uncorrected distance acuity in photopic conditions (p<0.001). Only two minor adverse events occurred. Conclusions: The ZMB00 1-Piece Tecnis multifocal IOL provides a good visual outcome at distance and near with minimal adverse effects.
Resumo:
The search by many investigators for a solution to the reading problems encountered by individuals with no central vision has been long and, to date, not very fruitful. Most textual manipulations, including font size, have led to only modest gains in reading speed. Previous work on spatial integrative properties of peripheral retina suggests that 'visual crowding' may be a major factor contributing to inefficient reading. Crowding refers to the fact that juxtaposed targets viewed eccentrically may be difficult to identify. The purpose of this study was to assess the combined effects of line spacing and word spacing on the ability of individuals with age-related macular degeneration (ARMD) to read short passages of text that were printed with either high (87.5%) or low contrast (17.5%) letters. Low contrast text was used to avoid potential ceiling effects and to mimic a possible reduction in letter contrast with light scatter from media opacities. For both low and high contrast text, the fastest reading speeds we measured were for passages of text with double line and double word spacing. In comparison with standard single spacing, double word/line spacing increased reading speed by approximately 26% with high contrast text (p < 0.001), and by 46% with low contrast text (p < 0.001). In addition, double line/word spacing more than halved the number of reading errors obtained with single spaced text. We compare our results with previous reading studies on ARMD patients, and conclude that crowding is detrimental to reading and that its effects can be reduced with enhanced text spacing. Spacing is particularly important when the contrast of the text is reduced, as may occur with intraocular light scatter or poor viewing conditions. We recommend that macular disease patients should employ double line spacing and double-character word spacing to maximize their reading efficiency. © 2013 Blackmore-Wright et al.
Resumo:
This paper is a cross-national study testing a framework relating cultural descriptive norms to entrepreneurship in a sample of 40 nations. Based on data from the Global Leadership and Organizational Behavior Effectiveness project, we identify two higher-order dimensions of culture – socially supportive culture (SSC) and performance-based culture (PBC) – and relate them to entrepreneurship rates and associated supply-side and demand-side variables available from the Global Entrepreneurship Monitor. Findings provide strong support for a social capital/SSC and supply-side variable explanation of entrepreneurship rate. PBC predicts demand-side variables, such as opportunity existence and the quality of formal institutions to support entrepreneurship.
Resumo:
Adopting another’s visual perspective is exceedingly common and may underlie successful social interaction and empathizing with others. The individual differences responsible for success in perspective-taking, however, remain relatively undiscovered. We assessed whether gender and autistic personality traits in normal college student adults predict the ability to adopt another’s visual perspective. In a task differentially recruiting VPT-1 which involves following another’s line of sight, and VPT-2 which involves determining how another may perceive an object differently given their unique perspective (VPT-2), we found effects of both gender and autistic personality traits. Specifically, we demonstrate slowed VPT-2 but not VPT-1 performance in males and females with relatively high ASD-characteristic personality traits; this effect, however was markedly stronger in males than females. Results contribute to knowledge regarding ASD-related personality traits in the general population and the individual differences modulating perspective-taking abilities.
Resumo:
Background: Proton Magnetic Resonance Spectroscopy (H-MRS) is a non-invasive imaging technique that enables quantification of neurochemistry in vivo and thereby facilitates investigation of the biochemical underpinnings of human cognitive variability. Studies in the field of cognitive spectroscopy have commonly focused on relationships between measures of N-acetyl aspartate (NAA), a surrogate marker of neuronal health and function, and broad measures of cognitive performance, such as IQ. Methodology/Principal Findings: In this study, we used H-MRS to interrogate single-voxels in occipitoparietal and frontal cortex, in parallel with assessments of psychometric intelligence, in a sample of 40 healthy adult participants. We found correlations between NAA and IQ that were within the range reported in previous studies. However, the magnitude of these effects was significantly modulated by the stringency of data screening and the extent to which outlying values contributed to statistical analyses. Conclusions/Significance: H-MRS offers a sensitive tool for assessing neurochemistry non-invasively, yet the relationships between brain metabolites and broad aspects of human behavior such as IQ are subtle. We highlight the need to develop an increasingly rigorous analytical and interpretive framework for collecting and reporting data obtained from cognitive spectroscopy studies of this kind. © 2014 Patel, Blyth, Griffiths, Kelly and Talcott.
Resumo:
Aim: To determine whether eyes implanted with the Lenstec KH-3500 "accommodative" intraocular lenses (IOLs) have improved subjective and objective focusing performance compared to a standard monofocal IOLs. Methods: 28 participants were implanted monocularly with a KH-3500 " accommodative" IOL and 20 controls with a Softec1 IOL. Outcome measures of refraction, visual acuity, subjective amplitude of accommodation, objective accommodative stimulus response curve, aberrometry, and Scheimpflug imaging were taken at ∼3 weeks and repeated after 6 months. Results: Best corrected acuity with the KH-3500 was 0.06 (SD 0.13) logMAR at distance and 0.58 (0.20) logMAR at near. Accommodation was 0.39 (0.53) D measured objectively and 3.1 (1.6) D subjectively. Higher order aberrations were 0.87 (0.85) μm and lower order were 0.24 (0.39) μm. Posterior subcapsular light scatter was 0.95% (1.37%) greater than IOL clarity. In comparison, all control group measures were similar except objective (0.17 (0.13) D; p = 0.032) and subjective (2.0 (0.9) D; p = 0.009) amplitude of accommodation. Six months following surgery, posterior subcapsular scatter had increased (p<0.01) in the KH-3500 implanted subjects and near word acuity had decreased (p<0.05). Conclusions: The objective accommodating effects of the KH-3500 IOL appear to be limited, although the subjective and objective accommodative range is significantly increased compared to control subjects implanted with conventional IOLs. However, this "accommodative" ability of the lens appears to have decreased by 6 months post-surgery.
Resumo:
Incorporation of catechols into polymers has long been of interest due to their ability to chelate heavy metals and their use in the design of adhesives, metal-polymer nanocomposites, antifouling coatings, and so on. This paper reports, for the first time, the reversible addition-fragmentation chain transfer (RAFT) polymerization of a protected catechol-inspired monomer, 3,4-dimethoxystyrene (DMS), using commercially available trithiocarbonate, 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid (DDMAT), as a chain transfer agent. Our identified RAFT system produces well-defined polymers across a range of molecular weights (5-50 kg/mol) with low molar mass dispersities (Mw/Mn < 1.3). Subsequent facile demethylation of poly(3,4-dimethoxystyrene) (PDMS) yields poly(3,4-dihydroxystyrene) (PDHS), a catechol-bearing polymer, in quantitative yields. Semiquantitative zinc binding capacity analysis of both polymers using SEM/EDXA has demonstrated that both PDMS and PDHS have considerable surface binding (65% and 87%, respectively), although the films deposited from PDMS are of a better quality and processability due to solubility and lower processing temperatures. © 2014 American Chemical Society.
Resumo:
Reading and language abilities are heritable traits that are likely to share some genetic influences with each other. To identify pleiotropic genetic variants affecting these traits, we first performed a genome-wide association scan (GWAS) meta-analysis using three richly characterized datasets comprising individuals with histories of reading or language problems, and their siblings. GWAS was performed in a total of 1862 participants using the first principal component computed from several quantitative measures of reading- and language-related abilities, both before and after adjustment for performance IQ. We identified novel suggestive associations at the SNPs rs59197085 and rs5995177 (uncorrected P≈10 for each SNP), located respectively at the CCDC136/FLNC and RBFOX2 genes. Each of these SNPs then showed evidence for effects across multiple reading and language traits in univariate association testing against the individual traits. FLNC encodes a structural protein involved in cytoskeleton remodelling, while RBFOX2 is an important regulator of alternative splicing in neurons. The CCDC136/FLNC locus showed association with a comparable reading/language measure in an independent sample of 6434 participants from the general population, although involving distinct alleles of the associated SNP. Our datasets will form an important part of on-going international efforts to identify genes contributing to reading and language skills. Genome-wide association scan meta-analysis for reading and language ability. © 2014 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.
Resumo:
This chapter discusses engineering design and performance of various types of biomass transformation reactors. These reactors vary in their operating principle depending on the processing capacity and the nature of the desired end product, that is, gas, chemicals or liquid bio-oil. Mass balance around a thermal conversion reactor is usually carried out to identify the degree of conversion and obtain the amount of the various components in the product. The energy balance around the reactors is essential for determining the optimum reactor temperature and the amount of heat required to complete the overall reactions. Experimental and pilot-plant testing is essential for proper reactor design. However, it is common practice to use correlation and valid parameter values in determining the realistic reactor dimensions and configurations. Despite the recent progress in thermochemical conversion technology, reactor performance and scale up potential are the subjects of continuing research.
Resumo:
Porous tin films as anode for lithium-ion batteries are electrodeposited on graphite paper. Homogeneous tin films with significant void space accommodate the volume change during tin lithiation/delithiation. Through adjusting the electrodeposition currents and time, the morphologies and void space of tin films on graphite paper are controllable. At fixed electrodeposition current densities, the prolonged electrodeposition time plays the role in growing big tin particles and resulting the disappearance of void space among tin particles. The increased electrodeposition current plays the role to increase the quantity of tin seeds in thickness of tin film, and the void space among tin particles remains but the thick film limits its electrochemical performance. The tin films electrodeposited at an optimized current densities and for an optimized electrodeposition time, present the best electrochemical performance, because the tin nanoparticles are well dispersed on graphite substrate including void space. The tin film electrodeposited at 0.2 A cm-2 for 2 min shows the capacity of 1.0 mAh cm-2 after 50 charge/discharge cycles. The void space of tin film is very important for the best capacity and cyclic ability. The metallic tin film produced at 0.4 A cm-2 for 3 min remains the uniform and microporous structure after charge/discharge for 50 cycles.
Resumo:
Modern advances in technology have led to more complex manufacturing processes whose success centres on the ability to control these processes with a very high level of accuracy. Plant complexity inevitably leads to poor models that exhibit a high degree of parametric or functional uncertainty. The situation becomes even more complex if the plant to be controlled is characterised by a multivalued function or even if it exhibits a number of modes of behaviour during its operation. Since an intelligent controller is expected to operate and guarantee the best performance where complexity and uncertainty coexist and interact, control engineers and theorists have recently developed new control techniques under the framework of intelligent control to enhance the performance of the controller for more complex and uncertain plants. These techniques are based on incorporating model uncertainty. The newly developed control algorithms for incorporating model uncertainty are proven to give more accurate control results under uncertain conditions. In this paper, we survey some approaches that appear to be promising for enhancing the performance of intelligent control systems in the face of higher levels of complexity and uncertainty.
Resumo:
As the world’s natural resources dwindle and critical levels of environmental pollution are approached, sustainability becomes a key issue for governments, organisations and individuals. With the consequences of such an issue in mind, this paper introduces a unifying approach to measure the sustainability performance of socio-economic systems based on the interplay between two key variables: essentiality of consumption and environmental impact. This measure attributes to every system a ‘fitness’ value i.e. a quantity that reflects its ability to remain resilient/healthy by avoiding ecological, social and economic collapse as it consumes the available resources. This new measure is tested on a system where there is a limited supply of resources and four basic consumption types. The analysis has theoretical implications as well as practical importance as it can help countries, organisations or even individuals, in finding better ways to measure sustainability performance.