Research on Civil Aircraft Flight Test of Power Supply Quality Analysis

In the process of civil aircraft airworthiness, analyzing power quality is the key to verify whether the power supply system meets the requirements of the clause. This paper makes deep research on the domestic and foreign power supply quality standard files and detailed introduces the characteristics of the power supply quality standard files. Then, comparative and analysis give suggestions which tally with power supply quality test requirements. Finally, define the special power supply quality test method for the practical engineering specifically, and power supply quality test characteristic in civil aircraft flight test, to provide guidance help for the future civil aircraft models.

Automated Large Artery Occlusion Detection in Stroke: A Single-Center Validation Study of an Artificial Intelligence Algorithm

<b><i>Introduction:</i></b> Expediting notification of lesions in acute ischemic stroke (AIS) is critical. Limited availability of experts to assess such lesions and delays in large vessel occlusion (LVO) recognition can negatively affect outcomes. Artificial intelligence (AI) may aid LVO recognition and treatment. This study aims to evaluate the performance of an AI-based algorithm for LVO detection in AIS. <b><i>Methods:</i></b> Retrospective analysis of a database of AIS patients admitted in a single center between 2014 and 2019. Vascular neurologists graded computed tomography angiographies (CTAs) for presence and site of LVO. Studies were analyzed by the Viz-LVO Algorithm® version 1.4 – neural network programmed to detect occlusions from the internal carotid artery terminus (ICA-T) to the Sylvian fissure. Comparisons between human versus AI-based readings were done by test characteristic analysis and Cohen’s kappa. Primary analysis included ICA-T and/or middle cerebral artery (MCA)-M1 LVOs versus non-LVOs/more distal occlusions. Secondary analysis included MCA-M2 occlusions. <b><i>Results:</i></b> 610 CTAs were analyzed. The AI algorithm rejected 2.5% of the CTAs due to poor quality, which were excluded from the analysis. Viz-LVO identified ICA-T and MCA-M1 LVOs with a sensitivity of 87.6%, specificity of 88.5%, and accuracy of 87.9% (AUC 0.88, 95% CI: 0.85–0.92, <i>p</i> &#x3c; 0.001). Cohen’s kappa was 0.74. In the secondary analysis, the algorithm yielded a sensitivity of 80.3%, specificity of 88.5%, and accuracy of 82.7%. The mean run time of the algorithm was 2.78 ± 0.5 min. <b><i>Conclusion:</i></b> Automated AI reading allows for fast and accurate identification of LVO strokes with timely notification to emergency teams, enabling quick decision-making for reperfusion therapies or transfer to specialized centers if needed.

105 Cost Analysis for the Risk-Stratification of Febrile Infants ≤ 60 Days Old

Primary Subject area Emergency Medicine - Paediatric Background Fever in the first months of life is among the most common clinical problems in pediatric healthcare. Nearly 2% of all infants will be evaluated for fever in an Emergency Department (ED) and approximately 10% harbor life-threatening serious bacterial infections (SBIs). The Rochester criteria are most widely used criteria for risk-stratification and predate modern biomarkers including procalcitonin (PCT). Recently, a high-performing prediction rule incorporating PCT was derived by the Pediatric Emergency Care Applied Research Network (PECARN). At present, PCT is not available in all clinical settings, limited largely by test cost. Objectives Compare the medical costs associated with PECARN and Rochester risk-stratification strategies using contemporary price, epidemiologic and test characteristic data. Design/Methods We assessed hospital-level costs associated with the door-to-discharge care of all well-appearing febrile infants aged ≤ 60 days evaluated at an urban tertiary pediatric hospital between April 2016 and March 2019. Direct and indirect ED and inpatient costs were obtained from provincial Ministry of Health data. Real-world costs were then incorporated into a probabilistic model for a cohort of equal size using either Rochester or PECARN risk-stratification, accounting for the added incremental cost of PCT ($24.86CAD). Models used an 8.4% pooled SBI risk, and Sn/Sp for Rochester and PECARN of 94%/49% and 98%/63%, respectively. Modeling was calculated under 4 scenarios; true positive with hospitalization, false negative with return visit and hospitalization, false positive with hospitalization, true negative with ED discharge. All costs were calculated in Canadian dollars. Results During the 3-year study period, 1168 index infant encounters met inclusion and were analyzed for hospital trajectory costs. Median costs per infant were $323 (IQR $286-$393) for infants discharged from the ED with no SBI, $2356 (IQR $1858-$3120) for infants hospitalized with no SBI, $3150 (IQR $2352-$4201) for hospitalized infants treated for a SBI, and $3763 (IQR $2146-$5180) for infants discharged from the ED ultimately requiring hospitalization with a missed SBI. For a cohort of 1168 infants, cost-per-infant using PECARN risk-stratification was $1332 (IQR $1062-$1739), compared to $1515 (IQR $1198-$1992) using Rochester. PECARN criteria would be expected to produce an overall savings of 12.1% for the modeled cohort ($1,556,432 vs $1,769,339). Under pessimistic and optimistic model assumptions, total savings were 4.9% and 18.3%, respectively. Costs borne by families were not considered, nor were the indirect benefits of reduced unnecessary invasive testing, hospitalizations and broad-spectrum antibiotic use. Conclusion Risk-stratification of febrile infants using PECARN prediction rules would produce important cost-savings due to superior test characteristics offsetting upfront PCT-associated costs. Such a strategy would also likely result in unmodeled non-monetary family-centered and healthcare system benefits. Real-world cost-effectiveness studies are needed.

Examining Appropriacy of CFI/TLI Cutoff Value in Multiple-group CFA Test of Measurement Invariance to Enhance Accuracy of Test Score Interpretation

The most common effect size when using a multiple-group confirmatory factor analysis approach to measurement invariance is ΔCFI/TLI with a cutoff value of 0.01 (Cheung &amp; Rensvold, 2002). However, this recommended cutoff value may not be ubiquitously appropriate and may be of limited utility for some tests (e.g., measures using dichotomous items or different estimation methods, sample sizes, or model complexity). Moreover, prior cutoff value estimations often have ignored consequences resulting in using measures that more accurately estimate countries’ or learners’ proficiency for some countries or groups versus others. In this study, we investigate whether the cutoff value proposed by Cheung and Rensvold (ΔCFI/TLI=0.01) is appropriate across educational measurement contexts. Specifically, we investigated the performance of ΔCFI/TLI in capturing LOI at the scalar level in dichotomous items within item response theory on groups whose test characteristic curves differed by 0.5. Simulation results showed that the proposed cutoff value of 0.01 in ΔCFI/TLI was not appropriate to capture LOI under the study conditions, which may result in the misinterpretation of test results or inaccurate inferences.

Linguistic Distance and Translation Differential Item Functioning on Trends in International Mathematics and Science Study Mathematics Assessment Items

The 2015 Trends in International Mathematics and Science Study (TIMSS) involved 57 countries and 43 different languages to assess students’ achievement in mathematics and science. The purpose of this study is to evaluate whether items and test scores are affected as the differences between language families and cultures increase. Using differential item functioning (DIF) procedures, we compared the consistency of students’ performance across three combinations of languages and countries: (a) same language but different countries, (b) same countries but different languages, and (c) different languages and different countries. The analyses consisted of the detection of the number of DIF items for all paired comparisons within each condition, the direction of DIF, the magnitude of DIF, and the differences between test characteristic curves. As the countries were more distant with respect to cultures and language families, the presence of DIF increased. The magnitude of DIF was greatest when both language and country differed, and smallest when the languages were same, but the countries were different. Results suggest that when TIMSS results are compared across countries, the language- and country-specific differences which could reflect cultural, curriculum, or other differences should be considered.

Examinee Characteristics and their Impact on the Psychometric Properties of a Multiple Choice Test According to the Item Response Theory (IRT)

The aim of the current study is to provide improvement evaluation practices in the educational process. A multiple choice test was developed, which was based on content analysis and the test specification table covered some of the vocabulary of the applied statistics course. The test in its final form consisted of 18 items that were reviewed by specialists in the field of statistics to determine their validity. The results determine the relationship between individual responses and the student ability. Most thresholds span the negative section of the ability. Item information curves show that the items provide a good amount of information about a student with lower or moderate ability compared to a student with high ability. In terms of precision, most items were more convenient with lower ability students. The test characteristic curve was plotted according to the change in the characteristics of the examinees. The information obtained by female students appeared to be more than the information obtained by male students and the test provided more information about students who were not studying statistics in an earlier stage compared with students who did. This test clearly indicated that, based on the level of the statistics course, there should be a periodic review of the tests in line with the nature and level of the course materials in order to have a logical judgment about the level of the students’ progress at the level of their ability.

Comparison of four commercially available ELISA kits for diagnosis of Fasciola hepatica in Irish cattle

Background Fasciola hepatica is a liver parasite of mammals and it results in poor welfare outcomes and economic losses in ruminants. While faecal egg count is the test most commonly used for diagnosis, it does not indicate presence of migrating immature stages. Serological techniques increase sensitivity at all stages of the liver fluke infection. The aim of this study was to compare four commercially available ELISA tests for the diagnosis of F. hepatica. For this purpose, we tested three sample types; (i) known F. hepatica status sera from an experimental infection for the comparison of sensitivities and specificities, (ii) sera from pre- and post-flukicide-treated (albendazole, closantel, nitroxynil and triclabendazole) beef cattle to contrast the differences of seropositivity before and after treatment, and (iii) bulk tank milk samples from dairy herds sampled during high and low F. hepatica exposure periods for assessing seasonal variations with the four tests available. Samples were tested using ELISA kits supplied by four manufacturers (Ildana Biotech, IDEXX, Svanova, and Bio-X). Samples were analysed simultaneously and in duplicate. Results In the control population Ildana, IDEXX and Bio-X presented 100% sensitivity (Se) and specificity (Sp), Svanovir presented a Se of 59% and a Sp of 96%. In flukicide-treated beef cattle, kits highlighted decreasing antibody levels 90 days post-treatment in variable degrees. Finally, bulk milk showed a significant decrease in ELISA value between high and low fluke exposure periods with all tests studied. Conclusions Se and Sp found in the present study, confirm that Ildana, IDEXX and Bio-X are accurate for the detection of F. hepatica exposure in Irish cattle. Svanovir Se and Sp in this population, indicate that a larger study is necessary to confirm this test characteristic in Irish herds. In post-treatment use, Bio-X showed a consistent and significant decrease of ELISA value in all groups treated, denoting to be a reliable tool for assessing treatment effect at 90 days post-treatment. Finally, all tests showed to be a reliable tool for the F. hepatica monitoring of high and low exposure seasons, using bulk tank milk samples.

An analysis of Javanese language test characteristic using the Rasch model in R program

One skill required to solve a problem in the 21st century is communication. Two international languages that are important in communication and thought at school are English and German language. However, beside international language, the local language, such as the Javanese language, is also essential and need to be maintained. The purpose of this study is to analyze the Javanese language test characteristics. This study was explorative research with secondary data collected by documentation of 220 students responses to the 50 multiple choice item of Javanese language test in the 11th grade of vocational high school. Data were analyzed using the Rasch model assisted by R program. Rasch model fits the data with 42 items after three times calibration. Based on difficulty level, ICC, and items reliability, there were 28 of 42 items (66.67%) that were good. This study finds out that generally, the Javanese language test is in the moderate category of difficulty. Hence, the need of evaluating the Javanese language test to make a better test that gives more accurate information about examinees' ability is crucial. The evaluation of the Javanese language test can be used to plan the next learning to get better Javanese language learning.

A Comparative Evaluation of Kernel Equating and Test Characteristic Curve Equating

This study compares the kernel equating (KE) and test characteristic curve (TCC) equating methods using the nonequivalent anchor test equating design. In this Monte Carlo study, four independent variables were examined: sample size, test length, average form discrimination, anchor test reliability, and the percentage of anchor items. For each condition, there were 100 replications. To assess the performance of TCC equating and KE, the differences between the examinee parametric true scores and the equated estimated expected true scores were examined. The equated scores were based on the average across replications for each condition. Generally speaking, both KE and TCC equating produced accurate results, although KE tended to perform better than TCC on the parametric true score scale across conditions. Past research and the current study’s results seem to indicate that KE should be strongly considered for most equating situations, particularly in light of its flexibility.