Search

Kubernetes is a free, open-source container orchestration system for deploying and managing Docker containers that host microservices. Kubernetes cluster logs help in determining the reason for the failure. However, as systems become more complex, identifying failure reasons manually becomes more difficult and time-consuming. This study aims to identify effective and efficient classification algorithms to automatically determine the failure reason. We compare five classification algorithms, Support Vector Machines, K-Nearest Neighbors, Random Forest, Gradient Boosting Classifier, and Multilayer Perceptron. Our results indicate that Random Forest produces good accuracy while requiring fewer computational resources than other algorithms. &nbsp

Le holisme de la réfutation, outhèse de Duhem-Quine, affirme que nous ne pouvons pas tester isolément une hypothèse scientifique, mais seulement des ensembles d’hypothèses. Ainsi, en cas d’échec d’un test, nous pouvons seulement conclure qu’au moins une hypothèse d’un ensemble est falsifiée, mais nous ne pouvons pasdéterminer laquelle.Bien que cette thèse soit partagée par Duhem et Quine, on néglige régulièrementdes différences entre leurs analyses, alors qu’ilsne s’appuient pas sur les mêmes arguments, et parviennent à des conclusions qui se contredisent sur des points essentiels. Nous proposonsdans cet articled’exposer leholisme duhemien, et de le comparer au holisme quinien.Nouscherchons surtout à montrer que le holisme duhemien n’empêche pasla falsifiabilité des hypothèses scientifiques.

Introduction To evaluate the effect of repeating test failures using an automated, non‐sequencing based non‐invasive prenatal testing test on a general‐risk population in Finland. Material and Methods A total of 545 samples from women who represent the average‐risk population in Oulu, Finland were analyzed with Vanadis® non‐invasive prenatal testing. Repeat testing of test failures was performed using a second sample. Results before and after repeat testing were compared with the reference outcome, as determined by clinical examination of neonates. Results There were eight test failures after first‐pass analysis, representing 1.5% of samples (95% CI 0.6%‐2.9%). Seven out of eight failures could be resolved by analysis of a second sample, thereby reducing the test failure rate from 1.5% to 0.2% (95% CI 0.0%‐1.0%). Conclusions Repeating test failures with a second plasma sample could significantly reduce the effective failure rate, thereby providing a way to effectively minimize test failures and further improving clinical utility and test performance.

Objectives: This study evaluated the efficacy of conversion test performed at 40 J (defibrillation margin ≥40 J), and factors potentially associated with test failure were identified. Background: Current subcutaneous implantable cardioverter-defibrillator (S-ICD) devices deliver a maximum of 80 J. Functional defibrillation testing is recommended at S-ICD implantation, and it is usually conducted by delivering a shock energy of 65 J to ensure a safety defibrillation margin ≥15 J. Although high rates of successful conversion were reported at 65 J, limited data exist on the defibrillation margin extent. Methods: Ventricular fibrillation was induced and conversion test was performed by delivering a 40-J shock in 308 patients. Success was defined as termination of ventricular fibrillation by the first shock delivered in standard polarity. The S-ICD system positioning was evaluated with the PRAETORIAN score using bidirectional chest X-rays. Results: The generator was positioned in an intermuscular pocket in 301 patients (98%) and the lead was implanted by means of a 2-incision technique. The PRAETORIAN score was 50 (OR: 2.93; 95% CI: 1.26 to 6.83; p = 0.013) were independently associated with conversion failure. Conclusions: The authors showed a high rate of defibrillation success with 40-J shocks in S-ICD systems implanted by means of modern surgical techniques. The variables associated with shock failure were male gender, higher body mass index, and suboptimal device position according to the PRAETORIAN score.

Purpose The readability and comprehensibility of Learner's Permit Knowledge Test practice questions and the relationship with test failure rates across states and the District of Columbia were examined. Method Failure rates were obtained from department representatives. Practice test questions were extracted from drivers' manuals and department websites and examined for readability using Flesch–Kincaid Grade Level and comprehensibility using Question Understanding Aid. The influence of readability and comprehensibility on test failure rates was explored. Results The average failure rate from reporting jurisdictions was 42.76%. In total, 11 out of 28 jurisdictions reported that test takers fail more than half the time, while 25 out of 28 reported that test takers fail at least a quarter of the time. While 33.09% of the variability in failure rates could be accounted for by syntactic complexity of the questions, 54.18% could be accounted for by the reading ease. Discussion With few exceptions, test failure rates are systematically high across the United States. The current findings suggest that these tests may be inappropriately biased against individuals with lower levels of literacy and language ability. Implications for test developers and clinicians are discussed.

Purpose The percentage of a maternal cell-free DNA (cfDNA) sample that is fetal-derived (the fetal fraction; FF) is a key driver of the sensitivity and specificity of noninvasive prenatal screening (NIPS). On certain NIPS platforms, >20% of women with high body mass index (and >5% overall) receive a test failure due to low FF (

We present an algorithm and discussion for minimizing processing and testing costs of a semiconductor manufacturing line. The core concept is that the testing at each process step has a nonzero cost. We derive the mathematical criteria to choose optimally, based on all future processing and testing costs and test failure probabilities, whether or not to perform testing at each process step. The formulation and implementation of the algorithm is necessarily an “engineering-side” activity. Yet, as the goal is the optimization of the business pertaining to processing step costs, the Chief Financial Officer has a critical role to play. Both Finance and Engineering must collaborate in the optimal testing platform we propose. Finance, rather than Engineering, bears the fiduciary and management responsibility to estimate and report processing and testing costs in the financial statements.

External quality assessment (EQA) schemes assess the performance of predictive biomarker testing in lung and colorectal cancer and have previously demonstrated variable error rates. No information is currently available on the underlying causes of incorrect EQA results in the laboratories. Participants in EQA schemes by the European Society of Pathology between 2014 and 2018 for lung and colorectal cancer were contacted to complete a survey if they had at least one analysis error or test failure in the provided cases. Of the 791 surveys that were sent, 325 were completed including data from 185 unique laboratories on 514 incorrectly analyzed or failed cases. For the digital cases and immunohistochemistry, the majority of errors were interpretation-related. For fluorescence in situ hybridization, problems with the EQA materials were reported frequently. For variant analysis, the causes were mainly methodological for lung cancer but variable for colorectal cancer. Post-analytical (clerical and interpretation) errors were more likely detected after release of the EQA results compared to pre-analytical and analytical issues. Accredited laboratories encountered fewer reagent problems and more often responded to the survey. A recent change in test methodology resulted in method-related problems. Testing more samples annually introduced personnel errors and lead to a lower performance in future schemes. Participation to quality improvement projects is important to reduce deviating test results in laboratories, as the different error causes differently affect the test performance. EQA providers could benefit from requesting root cause analyses behind errors to offer even more tailored feedback, subschemes, and cases. Supplementary Information The online version contains supplementary material available at 10.1007/s00428-020-02966-7.

Objective To evaluate the test accuracy of non-invasive prenatal testing (NIPT) for fetal trisomy 21, 18, and 13 using cell-free (cf) DNA analysis in maternal plasma with microarray quantitation. Method Systematic review and meta-analysis. Searches in MEDLINE, Pre-MEDLINE, EMBASE, Web of Science, and the Cochrane Library to 09.07.2018. Results Five studies analyzing 3074 samples, including 187 trisomy 21, 43 trisomy 18, and 19 trisomy 13 cases, were identified. Risk of bias was high in all studies, introduced particularly by exclusions from analysis and by the role of the sponsor. Sensitivity of microarray-based cfDNA testing was 99.5% (95%CI 96.3%-99.9%) for trisomy 21, 97.7% (95%CI 87.9%-99.6%) for trisomy 18, and 100% (95%CI 83.2%-100%) for trisomy 13. Specificity was 100% (95% CI 99.87%-100%) for trisomy 21, 99.97% (95%CI 99.81%-99.99%) for trisomy 18, and 99.97% (95%CI 99.81%-99.99%) for trisomy 13. Pooled test failure rate was 1.1%. A direct comparison of microarray- and sequencing-based cfDNA found equivalent test accuracy. Conclusion Included studies suggest that NIPT using microarray-based cfDNA testing has high sensitivity and specificity for detecting fetal trisomy 21, 18, and 13. However, the evidence base is small and at high risk of bias.

A test fails and despite an investigation by a developer there is no fault found (NFF). Large software systems are often released with known failing and flaky tests. In this work, we quantify how often a test fails and does not find a fault. We conduct a case study on 9.9 million test runs of 10k tests across four releases of a large project at Ericsson. For each test, we mine the rate of NFF test failures over total runs for each release, i.e. NFFRate. We compare the current level of test failure with the number of NFF failures during the stabilization period of the prior release, i.e. StableNFFRate. Using the binomial distribution, we are able to determine which tests exhibit a statistically larger number of failures relative to their expected StableNFFRate. These unstable tests need to be prioritized for re-run and potentially investigated to determine if there is a fault or if the test needs to be fixed or modified. Our work has had an impact on Ericsson’s testing practices with testers using the NFFRate to determine which tests are the “flakiest" and need to be fixed or moved into an earlier, virtualized unit test stage. Testers also use our tool and technique to prioritize the statistically unstable tests failures for investigation and to examine longterm trends of test failures that may indicate a fault.

Continuous integration advocates to run the test suite of a project frequently, e.g., for every code change committed to a shared repository. This process imposes a high computational cost and sometimes also a high human cost, e.g., when developers must wait for the test suite to pass before a change appears in the main branch of the shared repository. However, only 4% of all test suite invocations turn a previously passing test suite into a failing test suite. The question arises whether running the test suite for each code change is really necessary. This paper presents continuous test suite failure prediction, which reduces the cost of continuous integration by predicting whether a particular code change should trigger the test suite at all. The core of the approach is a machine learning model based on features of the code change, the test suite, and the development history. We also present a theoretical cost model that describes when continuous test suite failure prediction is worthwhile. Evaluating the idea with 15k test suite runs from 242 open-source projects shows that the approach is effective at predicting whether running the test suite is likely to reveal a test failure. Moreover, we find that our approach improves the AUC over baselines that use features proposed for just-in-time defect prediction and test case failure prediction by 13.9% and 2.9%, respectively. Overall, continuous test suite failure prediction can significantly reduce the cost of continuous integration.

Objective Women with high body mass index (BMI) tend to have reduced fetal fraction (FF) during cell‐free DNA‐based noninvasive prenatal screening (NIPS), causing test failure rates up to 24.3% and prompting guidelines that recommend aneuploidy screening other than NIPS for patients with significant obesity. Because alternatives to NIPS are only preferable if they perform better, we compared the respective sensitivities at different BMI levels of traditional aneuploidy screening and a customized whole‐genome sequencing NIPS. Method The relationship between FF, aneuploidy, and BMI was quantified from 58 105 patients screened with a customized NIPS that does not fail samples because of low FF alone. Expected analytical sensitivity as a function of aneuploidy and BMI (eg, trisomy 18 sensitivity when BMI = 35) was determined by scaling the BMI‐ and aneuploidy‐specific FF distribution by the FF‐ and aneuploidy‐specific sensitivity calculated from empirically informed simulations. Results Across all classes of obesity and assuming zero FF‐related test failures, analytical sensitivity for the investigated NIPS exceeded that of traditional aneuploidy screening for trisomies 13, 18, and 21. Conclusion Relative to traditional aneuploidy screening, a customized NIPS with high accuracy at low FF and a low test‐failure rate is a superior screening option for women with high BMI., What's already known about this topic? Women with high body mass index (BMI) often receive a test failure on noninvasive prenatal screening (NIPS) because of low fetal fraction (FF).The American College of Medical Genetics and Genomics recommends offering traditional aneuploidy screening to patients with “significant obesity.”NIPS offerings differ in their efficacy at low FF. What does this study add? Irrespective of BMI and without FF‐based test failures, it is possible for a customized NIPS to provide all women with accurate prenatal screening.

With the rapid development of medical technology, the use of electrosurgical instruments is dramatically increased in various types of surgery. However, the damage of the insulation layer of the reusable electrosurgical instrument often causes surgical accidents. The procedures of packaging and cleaning contribute to many damages to insulating layer of reusable electrosurgical instruments. Various types of reusable electrosurgical instruments were detected for insulation failures, conduction failures, short-circuit by using a high-voltage detector, DIATEG (Morgate company). In addition, reusable electrosurgical instruments were detected for insulation failures after packaging and cleaning by different procedures. 13.1% (129/740) electrosurgical instruments had an insulation test failure; 6.2% (9/146) monopolar wires were with conduction failure; and 7.7% (16/207) bipolar wires were with short-circuit. Different packaging and cleaning procedures contribute to various degrees of damages to insulating property of reusable electrosurgical instruments. Insulation failure was a wide problem of reusable electrosurgical instruments, while fixed packaging method and mild cleaning procedures result in fewer damages to insulating property of reusable electrosurgical instruments.

Objective To investigate the factors associated with cell-free DNA test failure, and the optimal subsequent management of these pregnancies. Methods This was a retrospective study of 27,363 singleton pregnancies undergoing cell-free DNA testing. Women with cell-free DNA test failure were divided into a high-risk group and a low-risk group according to their indications. The subsequent management and pregnancy outcomes of these women were followed up. Results The rate of cell-free DNA test failure at the first sampling was 1.49%, and 78.4% of failures were due to a low fetal fraction. Of the 66 women who refused any subsequent management, an adverse pregnancy outcome was seen in 5 cases, all belonging to the high-risk group. Of the 13 low-risk women who chose second-trimester maternal serum screening, all obtained a low-risk maternal serum screening result and an unaffected pregnancy outcome. A redraw was chosen by 171 women, which yielded a result in 75.4% and their pregnancy outcomes were unaffected; 42 women had an uninformative result again and received an amniocentesis. As 158 women had an amniocentesis after the first sampling, this procedure was offered in 200 cases altogether. Abnormal genetic testing results were shown in six (3%, 6/200) cases, all in the high-risk group. Conclusions High-risk pregnant women with cell-free DNA test failure are at increased risk of adverse pregnancy outcomes. A second sampling for cell-free DNA test or maternal serum screening might be suggested to low-risk women. Invasive prenatal diagnosis should be offered to the high-risk patients, especially those with a second cell-free DNA test failure.

The introduction of liquid biopsies for the detection of EGFR mutations in non-small cell lung cancer patients (NSCLC) has revolutionized the clinical care. However, liquid biopsies are technically challenging and require specifically trained personnel. To facilitate the implementation of liquid biopsies for the detection of EGFR mutations from plasma, we have assessed a fully automated cartridge-based qPCR test that allows the automatic detection of EGFR mutations directly from plasma. We have analyzed 54 NSCLC patients and compared the results of the cartridge-base device to an FDA-approved assay. Detection of EGFR mutations was comparable but slightly lower in the cartridge-based device for L858R mutations (14/15 detected, 93%) and exon 19 deletions (18/20 detected, 90%). Unfortunately, 8/54 (15%) tests failed but increasing the proteinase K volume helped to recover 3/4 (75%) unsuccessful samples. In summary, the fully automated cartridge-based device allowed the detection of EGFR mutations directly from plasma in NSCLC patients with promising accuracy. However, protocol adjustments are necessary to reduce a high test failure rate.

Impression technique is one of the factors affecting restoration fit accuracy, which is a major aspect influencing its survival. The purpose of this study is to compare, in vivo, the effect of two commonly used Vinyl Polysiloxane (VPS) impression techniques on the metal framework fitting of fixed partial dentures. Ninety-two consecutive patients, diagnosed as partially edentulous, treated by fixed partial denture restorations, participated in the study. Group 1-impressions (n = 44) were subjected to the 1-step technique, while group 2 impressions (n = 48) were subjected the 2-step technique. Three accuracy assessment common methods: probe, tactile sense and radiographic test, were used to validate the clinical fit of the metal framework. Misfit was defined as even one test failure. Twenty-one (22.8%) out of 92 metal frameworks exhibited metal frameworks misfit, whereas the other 71 (77.2%) were found to be accurate. Group 1 presented significantly (p = 0.04) more metal frameworks misfit, 14/44 (31.8%) vs. 7/48 (14.6%). Restoration location (maxilla vs. mandible) had no statistically significant impact on the results (p = 0.461). The use of the VPS putty/wash 2-step impression technique is recommended to improve the clinical fit of fixed partial denture restorations.

Laboratories testing predictive biomarkers in lung and colorectal cancer are advised to participate in external quality assessment (EQA) schemes. This study aimed to investigate which corrective actions were taken by laboratories if predetermined performance criteria were not met, to ultimately improve current test practices. EQA participants from the European Society of Pathology between 2014 and 2018 for lung and colorectal cancer were contacted, if they had at least one analysis error or test failure in the provided cases, to complete a survey. For 72.4% of 514 deviating EQA results, an appropriate action was performed, most often including staff training (15.2%) and protocol revisions (14.6%). Main assigned persons were the molecular biologist (40.0%) and pathologist (46.5%). A change in test method or the use of complex techniques, such as next-generation sequencing, required more training and the involvement of dedicated personnel to reduce future test failures. The majority of participants adhered to ISO 15189 and implemented suitable actions by designated staff, not limited to accredited laboratories. However, for 27.6% of cases (by 20 laboratories) no corrective action was taken, especially for pre-analytic problems and complex techniques. The surveys were feasible to request information on results follow-up and further recommendations were provided. ispartof: DIAGNOSTICS vol:10 issue:10 ispartof: location:Switzerland status: published

PurposeThe percentage of a maternal cell-free DNA (cfDNA) sample that is fetal-derived (the fetal fraction; FF) is a key driver of the sensitivity and specificity of noninvasive prenatal screening (NIPS). On certain NIPS platforms, >20% of women with high body-mass index (and >5% overall) receive a test failure due to low FF (MethodsA scalable fetal-fraction amplification (FFA) technology was analytically validated on 1,264 samples undergoing whole-genome sequencing (WGS)-based NIPS. All samples were tested with and without FFA.ResultsZero samples had FFConclusionsFFA transforms low-FF samples into high-FF samples. By combining FFA with WGS-based NIPS, a single round of NIPS can provide nearly all women with confident results about the broad range of potential fetal chromosomal abnormalities across the genome.

Test-case prioritization (TCP) aims to detect regression bugs faster via reordering the tests run. While TCP has been studied for over 20 years, it was almost always evaluated using seeded faults/mutants as opposed to using real test failures. In this work, we study the recent change-aware information retrieval (IR) technique for TCP. Prior work has shown it performing better than traditional coverage-based TCP techniques, but it was only evaluated on a small-scale dataset with a cost-unaware metric based on seeded faults/mutants. We extend the prior work by conducting a much larger and more realistic evaluation as well as proposing enhancements that substantially improve the performance. In particular, we evaluate the original technique on a large-scale, real-world software-evolution dataset with real failures using both cost-aware and cost-unaware metrics under various configurations. Also, we design and evaluate hybrid techniques combining the IR features, historical test execution time, and test failure frequencies. Our results show that the change-aware IR technique outperforms stateof-the-art coverage-based techniques in this real-world setting, and our hybrid techniques improve even further upon the original IR technique. Moreover, we show that flaky tests have a substantial impact on evaluating the change-aware TCP techniques based on real test failures.

BACKGROUND: Developmental language disorders (DLDs) are the most common developmental disorders in children. For screening DLDs, speech ability (SA) is one of the most important indicators. METHODS: In this paper, we propose a solution for the fast screening of children’s DLDs based on a comprehensive SA evaluation and a deep framework of machine learning. Fast screening is crucial for promoting the prevalence and practicality of DLD screening which in turn is important for the treatment of DLDs and related social and behavioral abnormalities (e.g., dyslexia and autism). Our solution is focused on addressing the drawbacks existing in the previous DLD screening methods which include test failure due to text-based inducing material design and illiteracy of most young children, incomplete language evaluation indicators, and professional-reliant evaluation procedures. First, to avoid test failure, a novel comprehensive inducing procedure (CIP) with non-text (i.e., audio-visual) stimulus materials was designed that could cover a large range of modalities to adequately explore the comprehensive SA of the subjects. Second, to address incomplete language evaluation, a set of comprehensive evaluation indicators with full consideration of the characteristics of the children’s language acquisition is proposed; furthermore, to break the professional-reliant limitation, we specifically designed a deep framework for fast and accurate screening. RESULTS: Experimental results showed that the proposed deep framework is effective and professional with a 92.6% accuracy on DLD screening. Additionally, to provide a benchmark for the novel problem, we provide a CIP dataset with about 2,200 responses from over 200 children, which may also be useful for further DLD studies and insightful for the fast screening design of other behavioral abnormalities. CONCLUSIONS: Fast screening of children’s DLDs can be achieved at accuracy up to 92.6% by our proposed deep learning framework. For successful fast screening, an elaborated CIP with corresponding comprehensive evaluating indicators is necessary to be designed for children suspected to have DLDs.

The modes of failure, impact and corrective actions have been observed as an effective way to improve reliability, which is a feature used in various power grid fields. This needs continuous monitoring and evaluation of its operation to minimize the cost of the operation. The failures in the transformer are analyzed in detail to identify the reasons and the procedure to find out the solution for the same with enhanced capacity and reliability. Transformer have the most common failure known as winding failure which is detected in Hi-Pot test. Many historical findings of the examination have not showed any early indication of transformer failure, the outcome of the Hi-Pot test showed significant deformation in both primary and secondary winding. To reduce future recurrence corrective actions are suggested.

Background: Recent studies have suggested a possible association between heparin treatment at the time of cell-free DNA (cfDNA) testing and a non-reportable result. However, these studies lack of proper methodology and had a low level of proof to firmly incriminate heparin. Our objective was to investigate further the relationship between heparin treatment and cfDNA test results. Methods: Two complementary approaches were used for the demonstration. First, we conducted a retrospective analysis of a cohort of patients with a singleton pregnancy, screened for aneuploidies by using cfDNA, but with a non-reportable cfDNA result. We included patients between 2013 and 2016 including the patients from the DEPOSA study as controls. CfDNA testing was performed by massive parallel sequencing by using a whole-genome approach. A multiple logistic regression was used to account for the influence of the variables included. Second, we performed in vitro experiments on mimic samples containing increased concentrations of heparin. Results: Of 9867 singleton pregnancies tested during the inclusion period, 58 (0.59%) had a non-reportable result and were compared to 295 control patients. Fifteen (25.9%) and 20 (6.8%) patients were treated with heparin in the group with a non-reportable cfDNA result and with a successful assay, respectively. In multivariable analysis, an increased calculated risk at the first-trimester combined screening (OR 28.8 CI 9.76-85.15, p < 0.001), maternal weight (OR 1.03, CI 1.01-1.06, p = 0.01), and the presence of an autoimmune disease (OR 10.38, CI 1.62-66.53, p = 0.01) were the only characteristics associated with a non-reportable result. In vitro experiments showed that heparin had no impact on fetal fraction measurement or the final result, no matter what the dose tested. Conclusions: Treatment by heparin had no impact on cfDNA screening test for aneuploidies, while the presence of an autoimmune disorder is an independent predictor of a non-reportable result., SCOPUS: ar.j, info:eu-repo/semantics/published

Objective: To examine the distribution of risks for fetal trisomies after first-trimester combined screening in twins and to investigate different strategies for clinical implementation of cell-free DNA (cfDNA) testing. Methods: We retrospectively analyzed all twin pregnancies undergoing first-trimester combined screening over a 10 years’ period. The population was stratified according to various risk cut-offs, and we examined different screening strategies for implementation of cfDNA testing in terms of impact on invasive testing rate, cfDNA test failure rate, and economic costs. Results: We included 572 twin pregnancies: 480 (83.92%) dichorionic and 92 (16.08%) monochorionic. Performing a first-line combined screening and offering cfDNA testing to the group with a risk between 1 in 10 and 1 in 1,000, would lead to an invasive testing rate of 2.45%, and cfDNA testing would be performed in 22.20% of the population. This strategy would be cost-neutral compared to universal combined screening alone. Conclusions: First-trimester combined screening results can be used to stratify twin pregnancies into different risk categories and select those that could be offered cfDNA testing. A contingent screening strategy would substantially decrease the need for invasive testing in twins and it would be cost-neutral compared to combined testing alone.

In electric power transmission, 110 kV XLPE cables have been given a wide usage recently. Specific samples are selected as specimens of accelerated thermal aging tests and are tested at different temperatures. Once the value of the specimen elongation at break decreases to 50% of the initial value, the cable at this condition is no longer suitable to be tested. The data obtained in this condition are the standard of judgment as a test failure and are used for calculation of the residual life. The Arrhenius equation is used to calculate the residual life of the tested 110 kV XLPE cables based on the data obtained from the experiments. The calculation shows that the whole service life of a cable at different periods is consistent. Furthermore, the calculations prove that the method used to assess the cables' residual life is robust and reliable. The result of the experiment provide both theoretical and practical basis to replace 110 kV XLPE cables preventively.

It is important to quantify the effect of the root diameter, the embedment length of the root and load speed on the soil-root interface mechanical properties for studying the root anchorage. The soilroot interface mechanical properties can be obtained through the pullout force and root slippage curve (F-S curve). About 120 Pinus tabulaeformis single roots whose diameters ranged from 1 mm to 10 mm divided into 6 groups based on different root embedment length (50 mm, 100 mm and 150 mm) and different load velocity (10 mm·min-1, 50 mm·min-1, 100 mm·min-1 and 300 mm·min-1) were investigated using the pullout method. This study aims to explore the mechanical properties of the soil-root interface in the real conditions using the pullout test method. The results showed two kinds of pullout test failure modes during the experimental process: breakage failure and pullout failure. The results showed that the roots were easier to be broken when the root diameter was smaller or the loading speed was larger. The relationship between the maximum anchorage force and root diameter was linear and the linearly dependent coefficient (R2) was larger than 0.85. The anchorage force increased with the root embedment length. An increase of 10%-15% for the maximum anchorage force was found when load speed increased from 10 to 300 mm.min-1. The mean peak slippage of the root was from 13.81 to 35.79 mm when the load velocity varied from 10 to 300 mm.min-1. The study will be helpful for the design of slopes reinforced by vegetation and in predicting risk of uprooting of trees, and will have practical benefits for understanding the mechanism of landslide.

A comprehensive procedure for a mechanically fastened composite laminate joint (ASTM D5961 Proc. A, B) is demonstrated from fixture design to analysis of test results. The ASTM tests are applied to evaluate the standard laminate properties and the composite joints. Composite laminate mechanical joints were analyzed using the finite element method (FEM), and the results were compared to test results. A progressive failure analysis (PFA) was applied to the FEM to predict the overall failure behavior of the test specimens. Three laminate failure theories – maximum stress, maximum strain, and Tsai–Wu – were applied to the PFA to predict the test failure load, displacement and strength. The PFA method was suitable to predict the initial test range of test and maximum test load except for the excessive failure area.

IntroductionHandwriting disorder is commonly observed in Developmental Coordination Disorder (DCD) (87-88%) and is often noted in children with high Intellectual Quotient (HIQ).Two mainly pure DCD subtypes: ideomotor-DCD (IM), visuospatial/or visuoconstructional-DCD (VSC) and a mixed subtype (MX) were identified in the literature but nothing is known regarding IQ and dysgraphia.ObjectivesTo refine the specific clinical features of dysgraphia related to DCD subtypes regarding IQ levels.Methods Neurovisual, neuropsychological, neuropsychomotor functions, and handwriting performances of 38 children (6-to-12 years-old: mean 9y, SD 2.7) diagnosed with DCD (DSM-5 criteria) were collected. Two matched groups were analyzed according to their IQ: 19 (TC) typical children (IQ=90-110) and 19 HIQ children (IQ> 120).Results IQ scores were not significantly associated with dysgraphia. There isa significant difference between TC vs HIQ with a lower rate of IM-DCD respectively 11% vs 5% (p=.035) and 68% vs 37% for VSC-DCD (p=.03) but 21% vs 58% in MX-DCD (p=.41). Dysgraphia was significantly more present in TC group with MX-DCD and in HIQ with VSC-DCD. A negative correlation between Kho’s’ cubes test failure (p=.006), visual-spatial memory (p=.05) and VSC-DCD was noted in HIQ group. The deficit of visual spatial memory was significantly related to dysgraphia in HIQ children (p=.01) associated to visual gnosis impairment (p=.03).ConclusionsDysgraphia was significantly found with VSC-DCD subgroup in FIQ>120 with specific features of visual perception disorders suggesting more involvement of the right cortex. These results suggest that VSC-DCD in HIQ could be a neurovisual impairment rather than a pure VSC-DCD.

The precast concrete industry produces a substantial quantity of waste due to quality non-conformances. Rather than deposit them in landfill, these products can be crushed, generating recycled aggregate, a by-product that may be reintroduced in the manufacturing process. But, what would happen if the recycled concrete pieces were rejected again? Is it possible to recycle the recycle concrete? The purpose of this paper is to study the possibility of multi-recycling precast concrete, in one of its most popular precast industry types: self-compacting concrete. In this study three recycled cycles were carried out, all of them using 100% recycled aggregate. The results showed that the new concretes with recycled and multi-recycled coarse aggregates from precast concrete rejects performed equally well, even slightly higher in compressive strength compared with control concrete; the increases at 28 days were 7.7%, 10.9% and 13.8% for the first, second and third recycling cycle, respectively. The performances of recycled concretes were better than reported in previous research, which is owing to the high quality of precast concrete recycled aggregates. The precast concrete industry can be more eco-friendly with its new self-compacting concrete products, produced with aggregates recycled from quality test failure or old pieces after their service phase. With this, the precast concrete industry will close the recycling concrete circle, decreasing its environmental impact and incurring potential cost savings.

The EU6d Emission Regulation requires Real Driving Emissions as an additional type approval requirement within the 2017 - 2020 timeframe in order to take into account the influence of the road profile, the ambient conditions and the traffic situation as well as the behavior of the driver. The new test uses Portable Emissions Monitoring System (PEMS) to measure on-board emissions. The trip sequence shall consist of a urban, a rural and a motorway sections with specific requirements in terms of distance and average speed for each section. For example, the overall trip duration shall be between 90 and 120 minutes. Due to these strong requirements, the execution of RDE measurements has to be preceded by an accurate planning of the route to reduce test failure risk and, consequently, experimental costs. The aim of the present investigation is to present a procedure to build a cycle for real driving emissions that minimizes the distance, is robust with respect to the uncertainties of traffic conditions and satisfy the requirements of the regulations. The procedure has been applied to routes from and to the Department of Engineering for Innovation. Moreover, a preliminary analysis of the effect of instantaneous speed and acceleration on real drive emissions is presented.

Cold-formed steel hollow flange sections are structurally efficient compared to the conventional open channel sections. They can be of different forms including hollow flange I- and channel sections, which are generally fabricated by first cold-forming a single sheet to form the desired shape and then connecting their flange and web elements by continuous welding. Instead of welding, intermittently screw/rivet fastened or spot welded connection can also be used. A detailed investigation is currently under way on the structural performance characteristics of such intermittently screw/rivet fastened steel hollow flange sections. This paper presents the details of an experimental study performed to investigate the behaviour of built-up cold-formed steel hollow flange sections in compression, where more than 45 stub columns were tested. Both hollow flange I- and channel sections built-up using either single steel sheet or three steel elements were tested. Tests also included built-up hollow flange channel sections with stiffened web elements. Test results including the failure loads, load versus axial deformation plots and failure characteristics are presented in this paper. Test failure loads are compared with the predictions based on both effective width and direct strength methods to verify their adequacy in predicting the section compression capacity of built-up hollow flange sections. This paper has shown that although hollow flange I-sections made of three elements with a 100 mm fastener spacing can perform similar to continuously welded sections, hollow flange channel sections undergo premature failures even with a 50 mm fastener spacing, and the reasons are discussed.