Performance Descriptors Research Articles

Key Parameters for Urban Heat Island Assessment in A Mediterranean Context: A Sensitivity Analysis Using the Urban Weather Generator Model

Although Urban Heat Island (UHI) is a fundamental effect modifying the urban climate, being widely studied, the relative weight of the parameters involved in its generation is still not clear. This paper investigates the hierarchy of importance of eight parameters responsible for UHI intensity in the Mediterranean context. Sensitivity analyses have been carried out using the Urban Weather Generator model, considering the range of variability of: 1) city radius, 2) urban morphology, 3) tree coverage, 4) anthropogenic heat from vehicles, 5) building’s cooling set point, 6) heat released to canyon from HVAC systems, 7) wall construction properties and 8) albedo of vertical and horizontal surfaces. Results show a clear hierarchy of significance among the considered parameters; the urban morphology is the most important variable, causing a relative change up to 120% of the annual average UHI intensity in the Mediterranean context. The impact of anthropogenic sources of heat such as cooling systems and vehicles is also significant. These results suggest that urban morphology parameters can be used as descriptors of the climatic performance of different urban areas, easing the work of urban planners and designers in understanding a complex physical phenomenon, such as the UHI.

An Application of a Multicriteria Model to Assess the Quality of Local Governance

This article presents a method to assess the quality of local governance practices. The multicriteria decision analysis modeling approach is illustrated through a real application (Portuguese municipalities). To define the criteria, performance descriptors, and reference levels in each dimension of local governance, and to account for the differences in preference of scoring in each criterion, the judgments of legitimate stakeholders were considered through decision conferencing. The constructed “Municipal Governance Indicator” is calculated for the case of Lisbon to show the outputs of the model and its potential usefulness.

Advances in Electrocatalysis for Energy Conversion and Synthesis of Organic Molecules.

Ubiquitous electrochemistry is expected to play a major role for reliable energy supply as well as for production of sustainable fuels and chemicals. The fundamental understanding of organics-based electrocatalysis in alkaline media at the solid-liquid interface involves complex mechanisms and performance descriptors (from the electrolyte and reaction intermediates), which undermine the roads towards advance and breakthroughs. Here, we review and diagnose recently designed strategies for the electrochemical conversion of organics into electricity and/or higher-value chemicals. To tune the mysterious workings of nanocatalysts in electrochemical devices, we examine the guiding principles by which the performance of a particular electrode material is governed, thus highlighting various tactics for the development of synthesis methods for nanomaterials with specific properties. We end by examining the production of chemicals by using electrochemical methods, from selective oxidation to reduction reactions. The intricate relationship between electrode and selectivity encourages both of the communities of electrocatalysis and organic synthesis to move forward together toward the renaissance of electrosynthesis methods.

Race Pattern of Women’s 100-m Hurdles: Time Analysis of Olympic Hurdle Performance

Background: For control and effective management of training process in women’s 100-m hurdles event, the coaches, in addition to detailed biomechanical parameters, need also overall, more comprehensive technical parameters, called direct performance descriptors which are used for planning the distribution of an athlete’s efforts over the race. Purpose: The aim of this study was the investigation of the race behavior of elite women sprint hurdlers, on the basis of selected time parameters, and the examination of the existence of a common race pattern in high level hurdle performance. Method: The time data of the race performance between two consecutive Olympic Games were compared. The analyzing subjects consisted of all women 100-m hurdle finalists in Athens 2004 (n = 6) and all women 100-m hurdle finalists (n = 8) and semi-finalists (n = 14) in Beijing 2008. Results: No significant differences were revealed between the two competitions concerning to the means of approach run time, run-in time, intermediate touchdown times, interval times for the hurdle units and the corresponding average velocities. Significant relationship exists between the intermediate times and final performance. The time contribution of the first half of the race to the formation of the final performance is approximately equal to the second one and, generally the standardised time parameters show the existence of a common race pattern in high level hurdle performance. Conclusion: The presented biomechanical data provide coaches and athletes with valuable information about hurdle technique for effective interventions in the training process.

Instantaneous Versus Interval Speed Estimates of Maximum Locomotor Capacities for Whole-Organism Performance Studies

Numerous studies have demonstrated the ecological and social relevance of different aspects of animal locomotor performance, as locomotion is frequently required to capture prey, escape from predators, find mates and defend territories. Typically, maximal performance is quantified using two alternative methods: across distance intervals or across time intervals, the later by extracting the speed observed between a specified number of video frames. Here, we analyze how this choice may influence statistical inference and the derived biological interpretations. Our results indicate that data obtained using 10-cm intervals are categorized, not normally distributed, exhibit lower individual repeatabilities and have four times more variance compared to the data obtained by quantifying speeds across short time intervals. These results have important methodological implications, as they suggest that the choice of method of speed quantification substantially influences the quality and bias of maximal performance descriptors. This may in turn have a profound influence on ecomorphological inference, as it affects our capacity of detecting variation in performance within and across groups, and associations between locomotor performance and other traits.

Ranking nano-enabled hybrid media for simultaneous removal of contaminants with different chemistries: Pseudo-equilibrium sorption tests versus column tests

The underlying hypothesis of this study was that pseudo-equilibrium and column testing conditions would provide the same sorbent ranking trends although the values of sorbents' performance descriptors (e.g. sorption capacity) may vary because of different kinetics and competition effects induced by the two testing approaches. To address this hypothesis, nano-enabled hybrid media were fabricated and its removal performances were assessed for two model contaminants under multi-point batch pseudo-equilibrium and continuous-flow conditions. Calculation of simultaneous removal capacity indices (SRC) demonstrated that the more resource demanding continuous-flow tests are able to generate the same performance rankings as the ones obtained by conducing the simpler pseudo-equilibrium tests. Furthermore, continuous overlap between the 98% confidence boundaries for each SRC index trend, not only validated the hypothesis that both testing conditions provide the same ranking trends, but also pointed that SRC indices are statistically the same for each media, regardless of employed method. In scenarios where rapid screening of new media is required to obtain the best performing synthesis formulation, use of pseudo-equilibrium tests proved to be reliable. Considering that kinetics induced effects on sorption capacity must not be neglected, more resource demanding column test could be conducted only with the top performing media that exhibit the highest sorption capacity.

A two-stage assessment method for assessing oral language in early childhood

Although the teaching of children’s oral language is critical to both their social development and academic success, the assessment of oral language development poses many challenges for classroom teachers. The aim of the study is to develop an approach that: (i) enables teachers to assess oral language in a reliable, valid and comparable manner and (ii) provides information to support targeted teaching of oral language. The first stage of the study applies the method of pairwise comparisons to place exemplars on a scale where locations represent the quality of oral performances. The second stage involves teachers assessing oral narrative performances against the exemplars in conjunction with performance descriptors. The findings indicate that the method provides a valid and reliable way for classroom teachers to assess oral language of students aged approximately four to nine years. The assessment provides teachers with information about students’ oral story-telling ability along with information about t...

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Shea trees identified for agronomical performances were compared through leaf and fruit characteristics. Seventy adult trees were selected using purposive sampling from seven sites along a south-north climatic gradient covering four agro-climatic zones. The effects of two factors (type of performance and site) on leaf and fruit parameters were investigated. Results showed significant effect of the type of the performance as shea trees performant for pulp production had longer petiole and laminar, wider laminar basis and top and had longer, wider and heavier fruits with more abundant pulp as compared to those performant for butter production. The factor site was found significant for all leaf and fruits parameters but the effect of climatic gradient was rare. The leaves in Siby and Kaniko had the longest laminar and the widest laminar basis, but those in Kaniko and Noumoudama had the widest laminar as compared to all other sites. The leaves in Noumoudama had the shortest petiole as compared to the rest. The leaves in Nampossela, Zanzoni, Solosso and Noumoudama had the widest laminar top as compared to those of Kaniko, Siby and Fougatie. The longest fruits were observed at Nampossela, while the widest and heaviest fruits as well as the most abundant pulp were observed at Kaniko and the heaviest nuts were observed at Siby. The smallest and slightest fruits were observed at Noumoudama and Solosso in more arid zones, but often, not significantly different from some sites in wettest zones regarding certain fruit parameters. This study highlighted phenotypic descriptors of agronomical performance through the leaves and the fruits of this tree species. Key words: Agronomical performance, climatic gradient, leaf and fruit characteristics, Mali, Vitellaria paradoxa.

Biotic resistance by snails and fish to an exotic invasive aquatic plant

Abstract Hydrilla verticillata (Hydrocharitaceae) is an exotic invasive macrophyte that has caused severe ecological and economic damage worldwide. H. verticillata has invaded the main channel of the river in the Upper Paraná River floodplain (Brazil), but it has not become established in floodplain lakes. Although some abiotic factors have been shown to affect the success of H. verticillata invasions, the role of biotic interactions remains unclear. Here, we set a laboratory experiment investigating how interactions with resident species may influence the success of H. verticillata invasions in floodplain lakes. Based on field observations, we selected three species that represent the most probable ecological interactions negatively impacting the early establishment of H. verticillata: a herbivorous fish (Moenkhausia forestii: Characidae) and herbivorous gastropods in the genus Pomacea (Ampullariidae), both natives, and an exotic shredder fish (Astronotus crassipinnis: Cichlidae). The individual and combined effects of these species on the early phase of H. verticillata establishment were evaluated. The native gastropod had the greatest effect on limiting plant growth due to herbivory, whereas the small native herbivorous fish mostly consumed H. verticillata leaves, and the non‐native shredder fish dislodged the plants from the sediment, preventing their establishment and increasing the number of free propagules (plant fragments) of previously rooted plants. The experimental treatment that combined all three species tended to reduce plant performance descriptors. Our results indicate that biotic resistance may play an important role in reducing the early establishment of H. verticillata in the lakes of this Neotropical floodplain. However, the disturbance caused by the exotic shredder fish may have an undesirable effect at larger scales because it stimulated the production of propagules that may spread to other connected aquatic ecosystems.

Skeleton sled velocity profiles: a novel approach to understand critical aspects of the elite athletes’ start phases

The development of velocity across the skeleton start is critical to performance, yet poorly understood. We aimed to understand which components of the sled velocity profile determine performance and how physical abilities influence these components. Thirteen well-trained skeleton athletes (>85% of athletes in the country) performed dry-land push-starts alongside countermovement jump and sprint tests at multiple time-points. A magnet encoder attached to the sled wheel provided velocity profiles, which were characterised using novel performance descriptors. Stepwise regression revealed four variables (pre-load velocity, pre-load distance, load effectiveness, velocity drop) to explain 99% variance in performance (β weights: 1.70, –0.81, 0.25, –0.07, respectively). Sprint times and jump ability were associated (r ± 90% CI) with pre-load velocity (–0.70 ± 0.27 and 0.88 ± 0.14, respectively) and distance (–0.48 ± 0.39 and 0.67 ± 0.29, respectively), however, unclear relationships between both physical measures and load effectiveness (0.33 ± 0.44 and –0.35 ± 0.48, respectively) were observed. Athletes should develop accelerative ability to attain higher velocity earlier on the track. Additionally, the loading phase should not be overlooked and may be more influenced by technique than physical factors. Future studies should utilise this novel approach when evaluating skeleton starts or interventions to enhance performance.

Ag-Sn Bimetallic Catalyst with a Core-Shell Structure for CO2 Reduction.

Converting greenhouse gas carbon dioxide (CO2) to value-added chemicals is an appealing approach to tackle CO2 emission challenges. The chemical transformation of CO2 requires suitable catalysts that can lower the activation energy barrier, thus minimizing the energy penalty associated with the CO2 reduction reaction. First-row transition metals are potential candidates as catalysts for electrochemical CO2 reduction; however, their high oxygen affinity makes them easy to be oxidized, which could, in turn, strongly affect the catalytic properties of metal-based catalysts. In this work, we propose a strategy to synthesize Ag-Sn electrocatalysts with a core-shell nanostructure that contains a bimetallic core responsible for high electronic conductivity and an ultrathin partially oxidized shell for catalytic CO2 conversion. This concept was demonstrated by a series of Ag-Sn bimetallic electrocatalysts. At an optimal SnOx shell thickness of ∼1.7 nm, the catalyst exhibited a high formate Faradaic efficiency of ∼80% and a formate partial current density of ∼16 mA cm-2 at -0.8 V vs RHE, a remarkable performance in comparison to state-of-the-art formate-selective CO2 reduction catalysts. Density-functional theory calculations showed that oxygen vacancies on the SnO (101) surface are stable at highly negative potentials and crucial for CO2 activation. In addition, the adsorption energy of CO2- at these oxygen-vacant sites can be used as the descriptor for catalytic performance because of its linear correlation to OCHO* and COOH*, two critical intermediates for the HCOOH and CO formation pathways, respectively. The volcano-like relationship between catalytic activity toward formate as a function of the bulk Sn concentration arises from the competing effects of favorable stabilization of OCHO* by lattice expansion and the electron conductivity loss due to the increased thickness of the SnOx layer.

The best of both worlds

Relying on teachers’ assessments for the information currently provided by standardized test scores would save instructional time, better capture the true abilities of diverse students, and reduce the problem of teaching to the test. A California high school is implementing standards-based reporting, ensuring that teacher-issued grades function as reliable and valid descriptors of student academic performance. At the state level, the New Hampshire Department of Education is anchoring accountability in teacher-assessed performance tasks rather than in standardized tests. The article offers guidelines and caveats to those interested in pursuing this work.

Miniaturized decoupled slotted patch RFID tag antennas for wearable health care

In this article, a couple of two-layered RFID tag antenna designs exhibiting improved performance descriptors for on-body applications are presented. The antennas are designed to operate in the microwave band (2.4–2.48 GHz) ensuring high data transmission rates ideal for real-time subject monitoring applications. The radiating element of both the antennas is a slotted patch structure provisioned with a pair of T-shaped slots realized on a commercial FR4 substrate. The augmentation of a systematic sequence of narrow comb-like etchings into the design enhances the impedance bandwidth considerably. A high permittivity silicon layer embedded with the radiating patch provides resilience from the human body dielectric losses. A modified antenna design utilizing patch miniaturization technique, resulting in an overall footprint reduction by 32%, is also proposed. The designed tag antennas offer a gain of more than 1.8 dBi and an attractive read range greater than 6.8 m in the operating band.

Aerodynamics of aero-engine installation

This paper describes current progress in the development of methods to assess aero-engine airframe installation effects. The aerodynamic characteristics of isolated intakes, a typical transonic transport aircraft as well as a combination of a through-flow nacelle and aircraft configuration have been evaluated. The validation task for an isolated engine nacelle is carried out with concern for the accuracy in the assessment of intake performance descriptors such as mass flow capture ratio and drag rise Mach number. The necessary mesh and modelling requirements to simulate the nacelle aerodynamics are determined. Furthermore, the validation of the numerical model for the aircraft is performed as an extension of work that has been carried out under previous drag prediction research programmes. The validation of the aircraft model has been extended to include the geometry with through flow nacelles. Finally, the assessment of the mutual impact of the through flow nacelle and aircraft aerodynamics was performed. The drag and lift coefficient breakdown has been presented in order to identify the component sources of the drag associated with the engine installation. The paper concludes with an assessment of installation drag for through-flow nacelles and the determination of aerodynamic interference between the nacelle and the aircraft.

Facilitating the interpretation of English language proficiency scores: Combining scale anchoring and test score mapping methodologies

The aim of this study was to develop, for the benefit of both test takers and test score users, enhanced TOEFL ITP® test score reports that go beyond the simple numerical scores that are currently reported. To do so, we applied traditional scale anchoring (proficiency scaling) to item difficulty data in order to develop performance descriptors for multiple levels of each of the three sections of the TOEFL ITP. A (novel) constraint was that these levels should correspond to those established in an earlier study that mapped (i.e., aligned) TOEFL ITP scores to a widely accepted framework for describing language proficiency – the Common European Framework of Reference (CEFR). The data used in the present study came from administrations of five current operational forms of the recently revised TOEFL ITP test. The outcome of the effort is a set of performance descriptors for each of several levels of TOEFL ITP scores for each of the three sections of the test. The contribution, we believe, constitutes (1) an enhancement of the interpretation of scores for one widely used assessment of English language proficiency and (2) a modest contribution to the literature on developing proficiency descriptors – an approach that combines elements of both scale anchoring and test score mapping.

Using a Scoring Rubric to Assess the Writing of Bioethics Students.

Educators in bioethics have struggled to find valid and reliable assessments that transcend the "reproduction of knowledge" to target more important skill sets. This manuscript reports on the process of developing and grading a minimal-competence comprehensive examination in a bioethics master's degree program. We describe educational theory and practice for the creation and deployment of scoring rubrics for high-stakes performance assessments that reduce scoring inconsistencies. The rubric development process can also benefit the program by building consensus among stakeholders regarding program goals and student outcomes. We describe the Structure of the Observed Learning Outcome taxonomy as a mechanism for rubric design and provide an example of how we applied that taxonomy to define pass/fail cut scores. Details about domains of assessment and writing descriptors of performance are also presented. Despite the laborious work required to create a scoring rubric, we found the effort to be worthwhile for our program.

The Creation of Standard-Setting Videos to Support Faculty Observations of Learner Performance and Entrustment Decisions.

Entrustable professional activities (EPAs) provide a framework to standardize medical education outcomes and advance competency-based assessment. Direct observation of performance plays a central role in entrustment decisions; however, data obtained from these observations are often insufficient to draw valid high-stakes conclusions. One approach to enhancing the reliability and validity of these assessments is to create videos that establish performance standards to train faculty observers. Little is known about how to create videos that can serve as standards for assessment of EPAs.The authors report their experience developing videos that represent five levels of performance for an EPA for patient handoffs. The authors describe a process that begins with mapping the EPA to the critical competencies needed to make an entrustment decision. Each competency is then defined by five milestones (behavioral descriptors of performance at five advancing levels). Integration of the milestones at each level across competencies enabled the creation of clinical vignettes that were converted into video scripts and ultimately videos. Each video represented a performance standard from novice to expert. The process included multiple assessments by experts to guide iterative improvements, provide evidence of content validity, and ensure that the authors successfully translated behavioral descriptions and vignettes into videos that represented the intended performance level for a learner. The steps outlined are generalizable to other EPAs, serving as a guide for others to develop videos to train faculty. This process provides the level of content validity evidence necessary to support using videos as standards for high-stakes entrustment decisions.

Technical performance and match-to-match variation in elite football teams

ABSTRACTRecent research suggests that match-to-match variation adds important information to performance descriptors in team sports, as it helps measure how players fine-tune their tactical behaviours and technical actions to the extreme dynamical environments. The current study aims to identify the differences in technical performance of players from strong and weak teams and to explore match-to-match variation of players’ technical match performance. Performance data of all the 380 matches of season 2012–2013 in the Spanish First Division Professional Football League were analysed. Twenty-one performance-related match actions and events were chosen as variables in the analyses. Players’ technical performance profiles were established by unifying count values of each action or event of each player per match into the same scale. Means of these count values of players from Top3 and Bottom3 teams were compared and plotted into radar charts. Coefficient of variation of each match action or event within a player was calculated to represent his match-to-match variation of technical performance. Differences in the variation of technical performances of players across different match contexts (team and opposition strength, match outcome and match location) were compared. All the comparisons were achieved by the magnitude-based inferences. Results showed that technical performances differed between players of strong and weak teams from different perspectives across different field positions. Furthermore, the variation of the players’ technical performance is affected by the match context, with effects from team and opposition strength greater than effects from match location and match outcome.

Multivariate comparison of reverse osmosis and nanofiltration membranes through tree cluster analysis

Experimental trials are usually needed to integrate information reported on data sheets in order to properly drive membrane choice. It results in data-sets where each membrane is characterised by several performance descriptors. Multivariate data-mining (i.e. chemometrics) effectiveness in analysing such data-sets has been demonstrated through the comparison of seven commercial membranes. Each membrane was represented as an object described by 15 features got from trials with different single-component test solutions. Tree cluster analysis based on Ward amalgamation method was employed for multivariate data mining. The algorithm progressively grouped the membranes in clusters, adopting the Euclidean distance in the 15-dimensional feature space as a measure of similarity. Thus, a graphical output consisting into a similarity tree representing the membrane taxonomy was obtained. A restricted number of membranes, selected as representatives of each identified cluster, underwent to further experiments devoted to a systematic study on boron removal at various pH values.

Exploiting affine invariant regions and leaf edge shapes for weed detection

In this article, local features extracted from field images are evaluated for weed detection. Several scale and affine invariant detectors from computer vision literature along with high performance descriptors were applied. Field dataset contained a total of 474 plant images of sugar beet and creeping thistle, divided into six groups based on illumination, age, and camera to plant distance. To establish a performance baseline, leaf image retrieval potential of the selected features was first assessed on a publicly available leaf database containing flatbed scanned images of 15 tree species. Then a comparison with the field data retrieval highlighted the trade-off due to the field challenges. Adopting a comprehensive approach, edge shape detectors and homogeneous surface detecting affine invariant regions were fused. In order to integrate vegetation indices as local features, a new local vegetation color descriptor was introduced which used various combinations of color indices and offered a very high precision. Retrieval in the field data was evaluated group-wise. Although, the impact of the sunlight was found to be very low on shape features, but relatively higher precisions were obtained for younger plants under a shade (overall more than 80%). The weed detection accuracy was assessed using the Bag-of-Visual-Word scheme with KNN and SVM classifiers. The assessment showed that with an SVM classifier, a fusion of surface color and edge shapes boosted the overall classification accuracy to as high as 99.07% with a very low false negative rate (2%).