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The current traffic control system (TCS) is not the most efficient system present for regulating traffic. Hoping to solve this we come up with dynamic data recording systems which encompasses of RFID tag and reader. The traffic density at each lane is calculated based on count of RFID’s apprehended. Depending on the density, the TCS is assigned a value of 15 to 70 seconds in round robin method for control of vehicular congestion. This proposed model also uses image processing for the detection of ambulances and also an active RFID for tracking the real-time location of these assets or in high-speed environments such as that of tolling. This allows the passage of ambulances through dense traffic. This system hopes to achieve to reduce the needless wait of crowded side, to reduce the long traffic chains, and to allow emergencies (medical/ vigilante) quickly through the traffic. The major merits of the system are it prevents unnecessary waiting time when no cars are present at the opposite route, gives the commuting passengers a better and more comfortable driving experience through their journey.

• Unpackaged CIGS cells were exposed to damp heat conditions in four labs. • Three labs showed reductions in efficiency of 89 ± 4% after ~500 h. • Efficiency loss was mainly driven by loss in fill factor and V oc. • A fourth lab 97 ± 3% loss after 143 h due to exposure to liquid water. • Climate chamber modification resulted in similar degradation results for this lab. A round robin test was carried out in four PV laboratories to compare accelerated lifetime testing. Twenty commercial non-packaged CIGS solar cells of similar performance were spread and exposed to damp heat conditions (85 °C and 85% RH) for approximately 500 h. Their JV performance was monitored during the damp heat exposure. After the test, three of the labs reported average efficiency losses of 87 ± 4%, 89 ± 5% and 92 ± 1%, which are close to median degradation rates found in literature. A higher degradation rate (efficiency loss of 97 ± 3% after only 143 h) was observed in the fourth lab. This was attributed to a poorly designed ceiling window sealing, which caused liquid water pooling on the samples. After modifying the climate chamber, the experiment was repeated with similar samples and an efficiency loss of 72 ± 6% after 475 h was observed for this lab. [ABSTRACT FROM AUTHOR]

This work proposes Practical Byzantine Fault Tolerance (PBFT) ordering service needed for block formation in permissioned blockchain environments. Contrary to current PBFT implementations that only provide a single point of entry to the ordering service, we allow each ordering node to act as an entry point that proposes and conducts the consensus process of including new record in the distributed ledger. To ensure atomicity of record insertion in distributed ledger, we have developed a bandwidth reservation protocol that uses a modification of CSMA/CA protocol to regulate access to the broadcast medium formed by the P2P network of TCP connections between orderers. We have modeled record insertion service time in a cluster where ordering nodes have random position within Cartesian coordinate system. We have also modeled total request access time to the ledger which includes waiting time in the orderer's queue and record insertion time. These models are used to evaluate system performance under variable request rate ordering service, variable number of nodes and variable physical cluster dimensions. Our results show the interaction between decreased request waiting time in orderer's queue and increased contention among orderers when the number of orderers increases for the given total request arrival rate. This interaction is also investigated for two different physical cluster sizes which affect record insertion time. The interplay of request rate, number of orderers and physical cluster size determines system capacity expressed in total request rate. Our model can be used to make the trade-off between the required system capacity, number of orderers, and physical cluster dimensions under constraints on Byzantine fault rate. [ABSTRACT FROM AUTHOR]

Cloud computing has emerged as the primary choice for developers in developing applications that require high-performance computing. Virtualization technology has helped in the distribution of resources to multiple users. Increased use of cloud infrastructure has led to the challenge of developing a load balancing mechanism to provide optimized use of resources and better performance. Round robin and least connections load balancing algorithms have been developed to allocate user requests across a cluster of servers in the cloud in a time-bound manner. In this paper, we have applied the round robin and least connections approach of load balancing to HAProxy, virtual machine clusters and web servers. The experimental results are visualized and summarized using Apache Jmeter and a further comparative study of round robin and least connections is also depicted. Experimental setup and results show that the round robin algorithm performs better as compared to the least connections algorithm in all measuring parameters of load balancer in this paper. [ABSTRACT FROM AUTHOR]

Currently, embedded systems are composed of processors, memories, and Intellectual Property Cores (IP Cores) interconnected to develop a set of specific tasks. Therefore, the selection of an appropriate interconnection architecture is critical in terms of system performance and functionality. A Network-on-Chip provides an efficient and scalable interconnection solution when there are a large number of elements in the system. However, the bus-based interconnection system remains the best option to connect a few cores. The bus arbiter uses an allocation policy to select which IP Core obtains access to the bus. The so-called fair policies ensure that all processors in the system have the same opportunity to access the bus. However, they fail to offer a fair share of the bandwidth or transmission rate, especially when there are heterogeneous IP Cores. As a study case, we analyze an embedded aerospace system for earth observation. Different IP Cores preprocess satellite images at distinct execution times -and unbalanced processing ratesaffecting the delivery rate of images to earth. We study the phenomenon of uneven bus transmission rates due to improper bus allocation using policies such as Round Robin, FIFO, and Lottery. Also, we propose a metric to compute the maximum number of IP Cores without bus saturation. [ABSTRACT FROM AUTHOR]

The current traffic control system (TCS) is not the most efficient system present for regulating traffic. Hoping to solve this we come up with dynamic data recording systems which encompasses of RFID tag and reader. The traffic density at each lane is calculated based on count of RFID's apprehended. Depending on the density, the TCS is assigned a value of 15 to 70 seconds in round robin method for control of vehicular congestion. This proposed model also uses image processing for the detection of ambulances and also an active RFID for tracking the real-time location of these assets or in high-speed environments such as that of tolling. This allows the passage of ambulances through dense traffic. This system hopes to achieve to reduce the needless wait of crowded side, to reduce the long traffic chains, and to allow emergencies (medical/vigilante) quickly through the traffic. The major merits of the system are it prevents unnecessary waiting time when no cars are present at the opposite route, gives the commuting passengers a better and more comfortable driving experience through their journey. [ABSTRACT FROM AUTHOR]

Minimizing time cost in time-shared operating system is the main aim of the researchers interested in CPU scheduling. CPU scheduling is the basic job within any operating system. Scheduling criteria (e.g., waiting time, turnaround time and number of context switches (NCS)) are used to compare CPU scheduling algorithms. Round robin (RR) is the most common preemptive scheduling policy used in time-shared operating systems. In this paper, a modified version of the RR algorithm is introduced to combine the advantageous of favor short process and low scheduling overhead of RR for the sake of minimizing average waiting time, turnaround time and NCS. The proposed work starts by clustering the processes into clusters where each cluster contains processes that are similar in attributes (e.g., CPU service period, weights and number of allocations to CPU). Every process in a cluster is assigned the same time slice depending on the weight of its cluster and its CPU service period. The authors performed comparative study of the proposed approach and popular scheduling algorithms on nine groups of processes vary in their attributes. The evaluation was measured in terms of waiting time, turnaround time, and NCS. The experiments showed that the proposed approach gives better results. [ABSTRACT FROM AUTHOR]

The purpose of LTE-A technology is to provide high spectral efficiency, lower delay and stronger intercell interference control for a multi- user environment. The architecture of LTE basically contains E-UTRAN and evolved packet core. E-UTRAN is the combination of UE and ENodeB (enhanced node B) used to control the radio network. EPC provide end to end connection and backward capability with previous networks. Major entities included in EPC are P-GW, S-GW, HSS and MME. This new architecture fulfil the requirement of next-generation mobile networks for high connectivity and multiple type of networks. Heterogeneous network is one of them in which different power base stations like femtocell, picocell, and radio remote head deployed in a geographical area with in macrocell cell. It is one of the cost effective solution to provide high throughput and spectral efficiency and fairness for cell edge user. Deployment of femtocell improved the data rate and coverage in small regions like office, home, shopping mall and dense areas. Along with this an efficient fair sharing of resource allocation plays an important role in improving the performance of networks. This paper analysed the performance of round robin, resource fair, Max-throughput, best CQI and proportional fair LTE-A resource scheduling techniques on homogeneous networks. For heterogeneous networks a new cluster based proportional fair resource scheduling technique is proposed, which provides an efficient resource to the most sufferer user and improved fairness and cell edge user throughputs. In heterogeneous networks multiple femto cell were deployed in macro cell area. Access policies are applied on open and closed group. The performance is measured in terms of cell edge throughputs, peak throughputs, average throughputs, wideband SINR, spectral efficiency, and fairness index for homogeneous, heterogeneous networks and for user mobility. The performance result showed that Best CQI and MaxTP scheduler outperforms in throughput level and attains highest average cell throughput of 83 Mbps and UE average throughput of 20 mbps in homogeneous networks and approximately 43 Mbps in heterogeneous networks. Comparative result in heterogeneous network indicates that the proposed scheduler increases 2% gain in fairness and 1–1.89% gains in edge throughputs with respect to proportional fair scheduler and allocates 79% fair share resources among UE. Round robin scheduler delivered very poor throughput and fairness index in both homogeneous and heterogeneousnetworks. [ABSTRACT FROM AUTHOR]

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Many standardised durability testing methods have been developed for Portland cement-based concretes, but require validation to determine whether they are also applicable to alkali-activated materials. To address this question, RILEM TC 247-DTA ‘Durability Testing of Alkali-Activated Materials’ carried out round robin testing of carbonation and chloride penetration test methods, applied to five different alkali-activated concretes based on fly ash, blast furnace slag or metakaolin. The methods appeared overall to demonstrate an intrinsic precision comparable to their precision when applied to conventional concretes. The ranking of test outcomes for pairs of concretes of similar binder chemistry was satisfactory, but rankings were not always reliable when comparing alkali-activated concretes based on different precursors. Accelerated carbonation testing gave similar results for fly ash-based and blast furnace slag-based alkali-activated concretes, whereas natural carbonation testing did not. Carbonation of concrete specimens was observed to have occurred already during curing, which has implications for extrapolation of carbonation testing results to longer service life periods. Accelerated chloride penetration testing according to NT BUILD 443 ranked the tested concretes consistently, while this was not the case for the rapid chloride migration test. Both of these chloride penetration testing methods exhibited comparatively low precision when applied to blast furnace slag-based concretes which are more resistant to chloride ingress than the other materials tested. [ABSTRACT FROM AUTHOR]

We investigated the ability of undergraduate students to detect psychopathic personality traits in their new peers, after engaging in limited, naturalistic contact. Research has demonstrated that personality traits can be socially recognised in others. However, this research has not yet explored the recognition of psychopathic personality traits in newly encountered peers. This is important as some of these traits, such as manipulation, can have important social consequences in forming friendships. At the same time, manipulative tendencies only work best when not seen as such. To study the salience of psychopathic personality traits, undergraduate students (N = 101) took part in a round robin judgment paradigm during their orientation period of university. We found that participants were able to detect the Triarchic Psychopathy Measure's traits of Boldness and Disinhibition but not Meanness in their groups, using typical social judgments. However, Meanness was the only trait that notably related to judges reporting that they would not make friends with targets who showed more psychopathic personality traits. These results highlight the importance of psychopathic personality traits when students form first impressions and intentions to make friends. Future research should consider the influence of 'hidden' meanness even in sub-clinical populations. [ABSTRACT FROM AUTHOR]

This paper documents the round robin testing campaign carried out on a floating wind turbine as part of the EU H2020 MaRINET2 project. A 1/60th scale model of a 10 MW floating platform was tested in wave basins in four different locations around Europe. The tests carried out in each facility included decay tests, tests in regular and irregular waves with and without wind thrust, and tests to characterise the mooring system as well as the model itself. For the tests in wind, only the thrust of the turbine was considered and it was fixed to pre-selected levels. Hence, this work focuses on the hydrodynamic responses of a semi-submersible floating foundation. It was found that the global surge stiffness was comparable across facilities, except in one case where different azimuth angles were used for the mooring lines. Heave and pitch had the same stiffness coefficient and periods for all basins. Response Amplitude Operators (RAOs) were used to compare the responses in waves from all facilities. The shape of the motion RAOs were globally similar for all basins except around some particular frequencies. As the results were non-linear around the resonance and cancellation frequencies, the differences between facilities were magnified at these frequencies. Surge motions were significantly impacted by reflections leading to large differences in these RAOs between all basins.

Abstract Cloud computing is a ubiquitous network access model to a shared pool of configurable computing resources where available resources must be checked and scheduled using an efficient task scheduler to be assigned to clients. Most of the existing task schedulers, did not achieve the required standards and requirements as some of them only concentrated on waiting time or response time reduction or even both neglecting the starved processes at all. In this paper, we propose a novel hybrid task scheduling algorithm named (SRDQ) combining Shortest-Job-First (SJF) and Round Robin (RR) schedulers considering a dynamic variable task quantum. The proposed algorithms mainly relies on two basic keys the first having a dynamic task quantum to balance waiting time between short and long tasks while the second involves splitting the ready queue into two sub-queues, Q1 for the short tasks and the other for the long ones. Assigning tasks to resources from Q1 or Q2 are done mutually two tasks from Q1 and one task from Q2. For evaluation purpose, three different datasets were utilized during the algorithm simulation conducted using CloudSim environment toolkit 3.0.3 against three different scheduling algorithms SJF, RR and Time Slice Priority Based RR (TSPBRR) Experimentations results and tests indicated the superiority of the proposed algorithm over the state of art in reducing waiting time, response time and partially the starvation of long tasks.

A standardized nomenclature for reporting oncology biomarker variants is key to avoid misinterpretation of results and unambiguous registration in clinical databases. External quality assessment (EQA) schemes have revealed a need for more consistent nomenclature use in clinical genetics. We evaluated the propensity of EQA for improvement of compliance with Human Genome Variation Society (HGVS) recommendations for reporting of predictive somatic variants in lung and colorectal cancer. Variant entries between 2012 and 2018 were collected from written reports and electronic results sheets. In total, 4,053 variants were assessed, of which 12.1% complied with HGVS recommendations. Compliance improved over time from 2.1% (2012) to 22.3% (2018), especially when laboratories participated in multiple EQA schemes. Compliance was better for next‐generation sequencing (20.9%) compared with targeted techniques (9.8%). In the 1792 reports, HGVS recommendations for reference sequences were met for 31.9% of reports, for 36.0% of noncommercial, and 26.5% of commercial test methods. Compliance improved from 16.7% (2012) to 33.1% (2018), and after repeated EQA participation. EQA participation improves compliance with HGVS recommendations. The residual percentage of errors in the most recent schemes suggests that laboratories, companies, and EQA providers need to collaborate for additional improvement of harmonization in clinical test reporting. [ABSTRACT FROM AUTHOR]

Technology behind every communication systems, especially commercial applications requires periodic modifications to satisfy the subscriber's desires. A bulk of handheld radio access devices are emerging in the market every day. Since radio resources are limited and expensive, Device to device communication underlying New Radio (NR-gNodeB) access network is encouraged in fifth generation (5G) systems. But such system may be a catalyst for interference. At present, the research hotspot is to find ideal solution for resource allocation and interference management. This paper emphasis the requirements of 5G system and its physical layer design. Further the intention is to mitigate interference in such system so that functionalities of scheduling schemes such as Greedy, Round Robin and Proportional fair algorithms are analyzed for efficient resource allocation. The simulation results explore that, the coded generalized frequency division multiplexing (GFDM) system results in higher transmission rate. Also, coded GFDM with proportional fair scheduler results in high throughput and reduced latency with no compromise in its fairness. In summary, the proposed scheme could be a wise choice for reliable communication in smart cities. [ABSTRACT FROM AUTHOR]

• Round-robin for 36Cl and Cl nat of calcite intercomparison material CoCal-N. • First round-robin for 36Cl of feldspar intercomparison material CoFsp-N. • 36Cl and Cl nat concentrations indicate intra- and inter-laboratory consistency. • Initial consensus values show coefficients of variation below 1.3%. Two natural mineral separates, labeled CoCal-N and CoFsp-N, have been prepared to serve as intercomparison material (ICM) for in situ -produced cosmogenic 36Cl and natural chlorine (Cl nat) analysis. The sample CoCal-N is derived from calcite crystals in a Namibian lag deposit, while the sample CoFsp-N is derived from a single crystal of alkali-feldspar from a Namibian pegmatite. The sample preparation took place at the University of Cologne and a rotating splitter was used to obtain homogeneous splits of both ICMs. Forty-five measurements of CoCal-N (between 1 and 16 per facility) and forty-four measurements of CoFsp-N (between 2 and 20 per facility) have been undertaken by ten target preparation laboratories measured by seven different AMS facilities. The internal laboratory scatter of the 36Cl concentrations indicates no overdispersion for half of the laboratories and 3.9 to 7.3% (1σ) overdispersion for the others. We show that the CoCal-N and CoFsp-N splits are homogeneous regarding their 36Cl and Cl nat concentrations. The grand average (average calculated from the average of each laboratory) yields initial consensus 36Cl concentrations of (3.74 ± 0.10) × 106 at 36Cl/g (CoCal-N) and (2.93 ± 0.07) × 106 at 36Cl/g (CoFsp-N) at 95% confidence intervals. The coefficient of variation is 5.1% and 4.2% for CoCal-N and CoFsp-N, respectively. The Cl nat concentration corresponds to the lower and intermediate range of typical rock samples with (0.73 ± 0.18) µg/g in CoCal-N and (73.9 ± 6.8) µg/g in CoFsp-N. We discuss the most relevant points of the sample preparation and measurement and the chlorine concentration calculation to further approach inter-laboratory comparability. We propose to use continuous measurements of the ICMs to provide a valuable quality control for future determination of 36Cl and Cl nat concentrations. [ABSTRACT FROM AUTHOR]

Finite element analysis is a common tool that has been used for the past few decades to predict the mechanical behavior of bone. However, to our knowledge, there are no round-robin finite element analyses of long human bones with more than two participating biomechanics laboratories published yet, where the results of the experimental tests were not known in advance. We prepared a fresh-frozen human femur for a compression test in a universal testing machine measuring the strains at 10 bone locations as well as the deformation of the bone in terms of the displacement of the loading point at a load of 2 kN. The computed tomography data of the bone with a calibration phantom as well as the orientation of the bone in the testing machine with the according boundary conditions were delivered to seven participating laboratories. These were asked to perform a finite element analysis simulating the experimental setup and deliver their results to the coordinator without knowing the experimental results. Resultantly, four laboratories had deviations from the experimentally measured strains of less than 40%, and three laboratories had deviations of their numerically determined values compared to the experimental data of more than 120%. These deviations are thought to be based on different material laws and material data, as well as different material mapping methods. Investigations will be conducted to clarify and assess the reasons for the large deviations in the numerical data. It was shown that the precision of finite element models of the human femur is not yet as developed as desired by the biomechanics community. [ABSTRACT FROM AUTHOR]

In this research, we compared the Round Robin (RR) and the Proportional Fair (PF) algorithms for different user equipment density scenarios using voice and video traffic, to evaluate the key impact on performance of 5G mmwave network. This research simulated on NS3.27 with an integrated mmwave module. Based on the result, we found that the RR is a good choice for voice traffic. It has a throughput of 3.65% better than PF with similar fairness index. On the other hand, we found that the PF is the right choice for video traffic due to has better result for throughput. It has a throughput of 1.24% better than RR. For fairness index round robin has better result for voice and video traffic. [ABSTRACT FROM AUTHOR]

The development of Directional Medium Access Control (DMAC) strategies that allow to enhance the limitations due to the use of omnidirectional antennas in Mobile ad Hoc Networks (MANET), introduces several issues that need to be properly addressed such as the Deafness problem. The use of Smart Antenna Systems (SAS) along with Directional Request To Send (DRTS) and Directional Clear To Send (DCTS) could be not sufficient to mitigate the Deafness. In this regard, a sectorized antenna approach together with a frame scheduling mechanism can improve the overall MAC performance while limiting the Deafness; however, the employment of scheduling algorithms without priority such as the Round Robin could limit the network performance especially in terms of Packet Delivery Ratio (PDR) and fairness. For this reason, we propose two approaches: the A-MSDU (Aggregation MAC Service Data Unit) MAC and a WRR (Weighted Round Robin) MAC that could allow to overcome the limitations of the Round Robin scheme applied at MAC layer in order to have an high efficiency in the overall resource allocation. More specifically, obtained results show that, through the use of frame aggregation, it is possible to considerably reduce issues implied by Round Robin such as time slice and network overhead; WRR approach, instead, is able to enhance the overall network fairness by reducing the number of collisions provided by a directional MAC based on Round Robin scheduling; this aspect translates into higher PDR performance compared to Round Robin approach. [ABSTRACT FROM AUTHOR]

Data offloading helps to send computation intensive part of a mobile application tasks to the cloud, a resource rich environment, for execution and after the processing, the result is sent back to the mobile devices thereby minimizing the execution time and computational cost. A lot of these tasks having different requirements and nature compete for resources in the cloud; therefore, effective and clever scheduling method is required. There have been a lot of scheduling research works in Mobile Cloud Computing (MCC) but most have been to minimize execution time and energy consumption, little consideration has been given to how more sensitive and important are some tasks over others. This often leads to application failure of some critical mission and delay sensitive mobile applications; this endangers vital processes even lives. In this work, we developed a model to bridge this gap by giving cognizance to how more important and delay sensitive some applications' tasks are and at the same time, with fairness to other less important tasks using Adjustable Time Slice Round Robin(ATSRR) Scheduling method. The performance evaluation of this work was done using a developed simulator and it was established that more important and delay sensitive jobs were churned out more than less important tasks with minimized turnaround time and fairness to all jobs with ATSRR over other existing works. As a result, this model can find its application in a cloud environment whereby critical missions and delay sensitive mobile apps are serviced by the Cloud Service Provider. [ABSTRACT FROM AUTHOR]

α‐Synuclein is the major component of Lewy bodies and a candidate biomarker for neurodegenerative diseases in which Lewy bodies are common, including Parkinson's disease and dementia with Lewy bodies. A large body of literature suggests that these disorders are characterized by reduced concentrations of α‐synuclein in cerebrospinal fluid (CSF), with overlapping concentrations compared to healthy controls and variability across studies. Several reasons can account for this variability, including technical ones, such as inter‐assay and inter‐laboratory variation (reproducibility). We compared four immunochemical methods for the quantification of α‐synuclein concentration in 50 unique CSF samples. All methods were designed to capture most of the existing α‐synuclein forms in CSF ('total' α‐synuclein). Each of the four methods showed high analytical precision, excellent correlation between laboratories (R2 0.83–0.99), and good correlation with each other (R2 0.64–0.93), although the slopes of the regression lines were different between the four immunoassays. The use of common reference CSF samples decreased the differences in α‐synuclein concentration between detection methods and technologies. Pilot data on an immunoprecipitation mass spectrometry (IP‐MS) method is also presented. Our results suggest that the four immunochemical methods and the IP‐MS method measure similar forms of α‐synuclein and that a common reference material would allow harmonization of results between immunoassays. α‐Synuclein is a synaptic protein that forms intracellular Lewy body inclusions in Parkinson's disease and other so called synuclein aggregation disorders. There are several methods to measure α‐synuclein concentration in human cerebrospinal fluid, where it is a candidate diagnostic and prognostic biomarker. In the current paper, we compared the analytical characteristics of four immunochemical (MSD, BioLegnd, Adx, and Roche) and one mass spectrometry‐based method. Variance component analysis partitions the total variance associated with 49 sample measured by site, kit lot, and replicate. The results show that the different methods measure similar forms of α‐synuclein and that a common reference material would allow for assay harmonization, which will be important in studies evaluating drugs that target α‐synuclein pathology specifically. [ABSTRACT FROM AUTHOR]

Numerous imminent challenges face 5G technology, mm-Wave is a potential alternative technology for future networks. This happens because it offers greater bandwidth, multi-gigabit and low latency wireless links. With these advantages, a MAC scheduler is needed at the base station to allocate radio resources available for applications in high-speed and real-time data. The right scheduling algorithm greatly affects network performance. In our research reported in this paper, we compare round robin and proportional fair algorithm on NS3.27. We determine how the choice of the scheduler has a significant impact on network performance such as throughput, delay and fairness index. Our results show that round robin is better than proportinal fair: it has better performance than proportional fair in terms of: a 3.65 % throughput, 18.29% delay and 0.1 % fairness index. We conclude that round robin is a better choice scheduler for voice traffic. [ABSTRACT FROM AUTHOR]

In this paper, we evaluate the theoretical bit error probability (BEP) of round robin, centralized and distributed relay selection for cooperative systems. Centralized relay selection activates the relay with the largest end-to-end signal-to-noise ratio (SNR) using a central node that will collect and compare these SNRs. In distributed relay selection, each relay compares its SNR to a predefined threshold T and is activated only when its SNR is larger than T. The threshold T is numerically optimized to have the lowest BEP. The network contains three nodes: one node acting as a source and the other two as destination. One of the destinations is selected to relay the signal to other destination node. Round robin relay selection consists to alternatively assign a node as relay. We also study relay selection for cognitive radio networks. The relay node should generate interference to primary receiver lower than a predefined threshold β. [ABSTRACT FROM AUTHOR]

• NDE reliability study on realistic, multi-channel data-set for dissimilar metal weld. • Study found multi-channel data makes inspectors miss flaws in "peripheral" channels. • Accurate flaw sizing on dissimilar metal welds appeared exceedingly difficult. • Machine learning was shown to effectively alleviate limitations in human performance. Round-robin exercises have traditionally been laborious to arrange in non-destructive testing (NDT). The exercises have involved manufacturing of costly big mock-ups and then distributing them around the world to facilitate testing by numerous laboratories. This has limited both the number of such round robins and their scope. Often the round robins have contained small number of flaws and the representativeness of these flaws has been limited. Nevertheless, the few round robins that have been completed have yielded significant additional understanding on the capability of the used NDT methods and procedures. Recently, the increased use of automated inspections together with the development of virtual flaws (independently by Trueflaw and EPRI) has enabled a new type of round robin, where instead of moving samples around the world, the round robin is focused on the data analysis and only pre-acquired data files are distributed. In 2019–2020, first of a kind virtual round robin (VRR) was completed. The round-robin allowed for the first time to compare inspection performance from teams around the world with statistically significant number of flaws and with ultrasonic data representative for nuclear dissimilar metal weld inspection. The study resulted in important new insight into NDE reliability for nuclear applications. However, as a first of a kind study, the first virtual round robin also contained some significant limitations. In particular, the data sets distributed were limited in order to limit the effort needed from each participating inspector. The reduced amount of data acquired was compensated by using pre-optimized data gathering, possible only with prior knowledge on the flaws present. While these choices were well justified for the first round-robin, they also made direct comparison of VRR results and real-life inspector performance problematic. In addition, the first VRR focused primarily on flaw detection and the data was insufficient for sizing. To address these shortcomings of the first round robin, a second round robin was completed in 2021–2022. In this second round robin, more representative data was used for evaluation. In addition, increased emphasis on the hard-to-detect small flaws was put forward to get improved into detectability especially in the low end. The more representative data required much more significant effort from the inspectors, which reduced the participation as compared to the first round robin. Furthermore, the emphasis on difficult-to-detect cracks may have further deterred participation, as the exercise may have been seen as too challenging. While the number of downloaded data sets (23) was similar to previous exercise, the number of returned sets was reduced to 5, compared to previous 18. Despite the smaller than expected participation, the results revealed several interesting features. The results displayed marked variation. Also, the false call rate was significantly reduced, as compared to the previous study. This could be attributed to the more rich data set, which allowed more comprehensive evaluation and exclusion of potential false calls. The recent advances in machine learning (ML) for ultrasonics also introduced an interesting opportunity to compare machine learning results with the human inspectors. Developing an optimized machine learning model for the present data was outside the scope of this study. Instead, an independently developed model, if somewhat sub-optimal, was used. Thus, the results should not be taken as a measure of ML performance as such. Nevertheless, the comparison between human results and ML model are informative and illustrate the potential benefits of automated data evaluation. [ABSTRACT FROM AUTHOR]

Characterizing and testing photovoltaic modules requires carefully made measurements on important variables such as the power output under standard conditions. When additional data is available, which has been collected using a different measurement system and therefore may be of different accuracy, the question arises how one can combine the information present in both data sets. In some cases one even has prior knowledge about the ordering of the variances of the measurement errors, which is not fully taken into account by commonly known estimators. We discuss several statistical estimators to combine the sample means of independent series of measurements, both under the assumption of heterogeneous variances and ordered variances. The critical issue is then to assess the estimator’s variance and to construct confidence intervals. We propose and discuss the application of a new jackknife variance estimator devised by [1] to such photovoltaic data, in order to assess the variability of common mean estimation under heterogeneous and ordered variances in a reliable and nonparametric way. When serial correlations are present, which usually a ect the marginal variances, it is proposed to construct a thinned data set by downsampling the series in such a way that autocorrelations are removed or dampened. We propose a data adaptive procedure which downsamples a series at irregularly spaced time points in such a way that the autocorrelations are minimized. The procedures are illustrated by applying them to real photovoltaic power output measurements from two different sun light flashers. In addition, focusing on simulations governed by real photovoltaic data, we investigate the accuracy of the jackknife approach and compare it with other approaches. Among those is a variance estimator based on Nair’s formula for Gaussian data and, as a parametric alternative, two Bayesian models. We investigate the statistical accuracy of the resulting confidence resp. credible intervals used in practice to assess the uncertainty present in the data.

The aim of this work is to demonstrate the maturity of the TOPCon technology by conducting a round-robin on symmetrically processed lifetime samples in the leading European PV institutes EPFL, ISC, CEA-INES, ISFH, IMEC and Fraunhofer ISE within the H2020 funded project called HighLite. For all layers, dark saturation current-densities ranging between 2 and 10 fA/cm2 can be reported. Simultaneously, no metal induced recombination for the two lower sintering temperatures have been observed pointing towards a true passivated contact. Furthermore, contact resistivities below 10 mΩcm2 have been achieved. It seems that the industrial passivating contact matured to a fully passivated and conducting contact enabling full efficiency potential. The fact that this can be realized using either PECVD or LPCVD from various manufacturer is expected to drive costs down and contribute to the increased adoption of the TOPCon technology.