Laboratory investigations on the quality of leak tests and visual inspections of wastewater connection pipes carried out by specialist contractors

In addition to stability and operational safety, leak tightness is the permanent functional objective of wastewater pipes. Tests to determine the tightness of wastewater pipes can in some cases produce results that are worthy of discussion. Therefore, laboratory tests were carried out by 29 specialist contractors to obtain results on the quality of leak tests and visual inspections of connection pipes. The results showed that different test errors can be observed for leak test methods (air overpressure, air underpressure and water pressure). However, only in the case of the water pressure tests did the observed test errors occasionally lead to incorrect test results, i.e. the ‘leaking pipe’ was tested as ‘test passed (tight)’. The investigations into the accuracy (trueness and precision) of the test methods showed that all test methods examined were sufficiently accurate to determine the tightness of the connection pipes. In general, correct test results were achieved if the expert testers did not make any serious test errors and the test equipment used functioned properly. In contrast, the investigations on the quality of visual inspection showed that the procedure is not sufficiently reliable to fulfil all normative requirements regarding damage detection and naming as well as damage classification.

Constant optimization and feature standardization in multiobjective genetic programming

This paper extends the numerical tuning of tree constants in genetic programming (GP) to the multiobjective domain. Using ten real-world benchmark regression datasets and employing Bayesian comparison procedures, we first consider the effects of feature standardization (without constant tuning) and conclude that standardization generally produces lower test errors, but, contrary to other recently published work, we find much less clear trend for tree sizes. In addition, we consider the effects of constant tuning – with and without feature standardization – and observe that (1) constant tuning invariably improves test error, and (2) usually decreases tree size. Combined with standardization, constant tuning produces the best test error results; tree sizes, however, are increased. We also examine the effects of applying constant tuning only once at the end a conventional GP run which turns out to be surprisingly promising. Finally, we consider the merits of using numerical procedures to tune tree constants and observe that for around half the datasets evolutionary search alone is superior whereas for the remaining half, parameter tuning is superior. We identify a number of open research questions that arise from this work.

Methods for improving the accuracy of CIE tristimulus values of object color by calculation Part II: Improvement on measurement wavelength ranges

The previous paper (part I) analyzed test errors of the spectrophotometer and their reasons, then systematically investigated the algorithms to reduce measuring bandpass error and intervals error. This paper (part II) focuses on the influence of measurement wavelength ranges and their truncation errors, and some algorithms to overcome the truncation errors. CIE recommends that tristimulus values are calculated over a range of 360–830 nm. However, most spectrophotometers do not meet it. The reduction of measurement range will result in a measurement range error or a truncation error. In this study, five ranges commonly employed in practice are selected for investigating the truncation errors, and three extrapolation methods are used to extend the data to compensate for the measurement range loss. Results are obtained by employing 1301 Munsell color chips under illuminant D65 and CIE 1964 standard observer. For the standard 1-nm intervals, the narrower the range, the larger the truncation error. For the usual-measured 10-nm intervals, bandpass error and intervals error should be handled at the same time, 380–780 nm Table LWL gives the highest accurate outcomes, which even improve the accuracy of the range 360–750 nm to an acceptable level. Whereas, ranges of 360–700 nm and 400–700 nm still need extrapolation to reduce their truncation errors even with Table LWL. Three extrapolation methods of nearest, linear and second-order all reduce the truncation error, but for different ranges, algorithms and illuminants, the optimal method of extrapolation varies.

Remarks on pooling Coronavirus tests

Diagnostic testing for the novel Coronavirus is an important tool to fight the Covid-19 pandemic. However, testing capacities are limited. A modified testing protocol, whereby a number of probes are “pooled” (that is, grouped), is known to increase the capacity for testing. Here, we model pooled testing with a double-average model, which we think to be close to reality for Covid-19 testing. The optimal pool size and the effect of test errors are considered. Results show that the best pool size is three to five, under reasonable assumptions. Pool testing even reduces the number of false positives in the absence of dilution effects.

On the Number of Witnesses in the Miller–Rabin Primality Test

In this paper, we investigate the popular Miller–Rabin primality test and study its effectiveness. The ability of the test to determine prime integers is based on the difference of the number of primality witnesses for composite and prime integers. Let W ( n ) denote the set of all primality witnesses for odd n. By Rabin’s theorem, if n is prime, then each positive integer a < n is a primality witness for n. For composite n, the power of W ( n ) is less than or equal to φ ( n ) / 4 where φ ( n ) is Euler’s Totient function. We derive new exact formulas for the power of W ( n ) depending on the number of factors of tested integers. In addition, we study the average probability of errors in the Miller–Rabin test and show that it decreases when the length of tested integers increases. This allows us to reduce estimations for the probability of the Miller–Rabin test errors and increase its efficiency.

Directional Bias in Line Orientation Test Errors in Parkinson’s Disease

Objective Value in evaluating error subtypes on visuospatial line orientation tests has been reported. Directional bias metrics for line orientation test errors represent easily quantifiable data that have not previously been studied. We evaluated whether patients with a clinical condition known to affect visuospatial functioning (Parkinson’s disease [PD]) exhibited unique directional error patterns on the RBANS Line Orientation test relative to other neuropsychology-referred patients. Method We compared overall directional bias in errors, directional bias by line location (left or right line and visual field), and absolute error rates (regardless of direction) by line location in a retrospective sample of patients with PD and a sample of neuropsychology-referred patients without PD. Groups were roughly matched on age, education, gender, and overall level of cognitive impairment. Results Patients with PD exhibited higher rates of leftward bias in errors, both overall and for the left stimulus line in each pair. Directional bias error scores better predicted PD versus non-PD group status than RBANS Line Orientation raw scores. Classification accuracy data for these variables were modest in the entire sample but stronger in a subsample of patients with mild levels of overall cognitive impairment. Conclusions Directional bias metrics for line orientation tests represent easily quantifiable data with potential theoretical and clinical value. In our sample, patients with PD made more left-biased line orientation errors than other neuropsychology-referred patients. By themselves, directional bias scores may have limited diagnostic potential, but they may be useful in diagnostic classification models and may have implications for clinical care.

Pooling of coronavirus tests under unknown prevalence

Diagnostic testing for the novel coronavirus is an important tool to fight the coronavirus disease (Covid-19) pandemic. However, testing capacities are limited. A modified testing protocol, whereby a number of probes are ‘pooled’ (i.e. grouped), is known to increase the capacity for testing. Here, we model pooled testing with a double-average model, which we think to be close to reality for Covid-19 testing. The optimal pool size and the effect of test errors are considered. The results show that the best pool size is three to five, under reasonable assumptions. Pool testing even reduces the number of false positives in the absence of dilution effects.

Experimental Study on Collimation Characteristics of an ECRH System with a 28GHz/50kW Gyrotron

In this paper, the collimation characteristics of an electron cyclotron resonance heating (ECRH) system with a 28GHz/50kW gyrotron in EXL-50 are studied experimentally. Through using laser trackers and designing matching tooling, test errors of horizontal distances and vertical distances between the transmission line and the flange center are all within 1mm, which are less than 0.4% and 0.07% respectively. In addition, online beam spot test with a 150 ms short pulse from a 28 GHz gyrotron also proves good collimation characteristics of the ECRH system. Finally, spherical plasma is formed through injecting the microwave to the vacuum chamber.

A Prospective Study Evaluating the Effects of a Nutritional Supplement Intervention on Cognition, Mood States, and Mental Performance in Video Gamers

Cognitive function is critical for successful prolonged performance in eSports. This double-blind placebo-controlled study examined the effect of an inositol-enhanced arginine silicate oral supplement on cognitive performance and energy in eSports athletes. Sixty healthy men and women who spent 5 or more hours a week playing video games were randomly assigned to take supplement or placebo for 7 days. On day 1 and 7, before and 15 min after dosing, subjects completed the Trail Making Test (TMT), Parts A and B; Stroop Test; and Profile of Mood States (POMS) questionnaire, and then played a video game for 60 min. Immediately after, cognitive tests were repeated. Self-reported energy levels increased, anger decreased, and TMT-B test errors decreased in the supplement group compared to placebo (p < 0.05). Fatigue, TMT-B time, and TMT B-A score improved in the supplement group compared to baseline (p < 0.05). After 60 min of gaming, supplementation decreased Stroop Test errors and TMT-A time (p < 0.05). Adverse events were minimal and not different between groups. These data appear to support the use of the studies product (nooLVL®) in eSports gamers looking to improve their accuracy, decision making, and reaction time during gaming.

Reliability of Lateral Cephalometric Radiographs in the Assessment of the Upper Airway in Children: A Retrospective study

ABSTRACT Objectives To test the reliability of Lateral cephalometric radiographs (LCRs) for use in the assessment of the upper airway, hyoid bone, soft palate, and tongue. Materials and Methods The records of 57 healthy Chinese children from a nonhospital population (mean age = 12.6 years, SD = 0.5, 28 males and 29 females) who received two consecutive LCRs in the natural head posture were retrospectively analyzed. Fifteen linear, angular, and area measurements were used to describe the airway, hyoid bone, soft palate, and tongue. The reliability between the two LCRs was assessed with the intraclass correlation coefficient (ICC) and F-test. Errors were estimated with the Dahlberg and Bland-Altman method, and intra- and inter-assessor agreements were determined. Results Measurements of upper airway and hyoid bone had excellent method reliability, intra-assessor reliability, and inter-assessor reliability (ICC &gt; 0.8). However, the method reliability and the inter-assessor reliability for soft palate and tongue was less favorable (ICC from 0.60 to 0.96). Soft palate area and thickness were the most critical parameters. Intra-assessor reliability was greater than both method reliability and inter-assessor reliability (which were similar). Conclusions The measurement of upper airway morphology, defined as the intramural space, and of the hyoid bone position were highly reliable on LCRs of children. However, the limited reliability in the assessment of tongue and soft palate area may compromise the diagnostic application of LCRs to these structures.