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• A hybrid broadband and narrowband active sound profiling algorithm is proposed for active hybrid noise control. • Simulations of stationary and non-stationary hybrid noise sources prove the stability and robustness of the algorithm. • The proposed algorithm can selectively control the desired narrowband noise components with specific magnitudes in hybrid noise. • Real vehicle experiments, conducted using headrests, validate the theoretical analysis. The vehicle interior noise consists of both broadband road noise and narrowband engine order noise. Currently, the road noise control (RNC) system and engine noise control (EOC) system operate independently in engineering applications. This paper introduces a novel multi-channel hybrid broadband and narrowband active noise control (HBNANC) algorithm, designed to simultaneously attenuate road noise and engine order noise inside vehicles. On this basis, by integrating an error signal design (ESD) subsystem and a sinusoidal error separation (SES) subsystem, a multi-channel hybrid broadband and narrowband active sound profiling (HBNASP) algorithm is further proposed, enabling specific attenuation or amplification of individual narrowband components to meet subjective acoustic comfort requirements. The paper validates the algorithms' effectiveness and robustness through simulations, and real vehicle experimental measurements under various conditions. The research offers a comprehensive approach to enhancing the auditory experience inside vehicles, contributing to the advancement of active noise control technology. [ABSTRACT FROM AUTHOR]

The explicit consideration of a communication channel model in a feedback control loop is known to be constrained by a fundamental limitation for stabilizability on the channel signal-to-noise ratio (SNR) when the linear time invariant (LTI) plant model is unstable. The LTI modelling approach for real, usually nonlinear, processes compromises accuracy versus complexity of the resulting model. This in turn introduces a gap between the proposed model and the real process, which is known as the model uncertainty. In this paper we then study SNR limitations by considering the continuous-time scenario and the case of an additive coloured Gaussian noise (ACGN) channel with bandwidth limitation, for which we then quantify the infimal SNR subject to the simultaneous presence of plant, channel and noise model uncertainties. We observe, for the special case of memoryless additive white Gaussian noise (AWGN) channels, that the obtained SNR limitation subject to plant model uncertainty can be redefined as a channel capacity limitation for stabilization. • Signal transmission through communication channels is increasingly relevant in Control Theory. • Many relevant communication features can be considered: power, channel bandwidth, time delay, etc. • Control Theory require analysis tools for studying model uncertainty and communication features simultaneously. • The SNR approach can provide such analysis tool, and in turn better inform the controller design. [ABSTRACT FROM AUTHOR]

We propose novel quadratic performance tests for linear discrete-time impulsive systems based on viewing these systems as feedback interconnections of some non-impulsive linear system with an impulsive operator. In order to systematically analyze such interconnections, we employ the framework of integral quadratic constraints and propose novel constraints of this kind for capturing the behavior of the involved impulsive operator. As a major benefit, the modularity of this framework permits seamless extensions to interconnections affected by heterogeneous uncertainties in a straightforward fashion. This contrasts with alternative approaches which are based on capturing the system's impulsive behavior by means of a clock. Building upon the developed analysis criteria, we characterize the existence of non-impulsive estimators for such impulsive interconnections in a lossless fashion and in terms of linear matrix inequalities. Finally, our approach is illustrated by means of several numerical examples. [ABSTRACT FROM AUTHOR]

Societies face an increasing number of challenges due to climate change – including enhanced hydro-meteorological risk (HMR). Typically, HMRs are exacerbated by rapid urban development, ecosystem degradation, and water use changes. All though data is scarce and scattered, evidence-based case studies have shown that implementing Nature-based Solutions (NBS) can reduce HMR. With further influence from anthropogenic climate change and continuing ecosystem degradation, HMH are projected to increase in frequency and severity. Consequently, NBS implemented for HMR reduction will have to be robust enough to deal with HMHs that exceed their design criteria and/or expected performance. However, currently available literature does not adequately outline processes that aid in designing and evaluating of robust NBS for HMR reduction. In response to this gap in literature, this study developed a process for designing and evaluating robust NBS for water. In the present study, robust design of a NBS for water is illustrated using an existing flood risk management system and NBS (100-year-old traditional irrigation furrows) in an agricultural area situated within the floodplain of the Chao Phraya River basin in the Pathum Thani province, Thailand. The robustness of the existing NBS for water is then evaluated through robust design and quantified through the construction of a responsive curve. Once the robustness of the existing NBS for water is quantified, an iterative process is used to enhance individual characteristics of the flood risk management system – resulting in efficient use of the flood water storage capacity offered by the existing NBS. [ABSTRACT FROM AUTHOR]

Background Traditional Youden chart can be distorted by non-normally distributed data. Here, an optimized Youden chart was developed and compared with the traditional and trimmed traditional Youden charts. Methods The urea concentrations were determined by 28 laboratories to provide data for the construction of Youden charts. Normality of these data was tested. Outliers were excluded prior to construction of the trimmed traditional Youden chart. Non-robust and robust estimators were computed to construct the traditional and robust Youden charts, respectively. Robust between-laboratory z -score (ZB i ) and within-laboratory z -score (ZW i ) were obtained to assess whether or not these charts can reasonably present the urea results. Expected outcomes were the points related to acceptable (|ZB i | and |ZW i | ≤ 2), questionable (2 < |ZB i | < 3 and/or 2 < |ZW i | < 3), and unacceptable (|ZB i | and/or |ZW i | ≥ 3) results fall inside, on/near, and outside the ellipse, respectively. Results Only the data from lot 201111 are non-normally distributed. Five- and 2-pair outliers are excluded from the data of lots 201111 and 201112, respectively. The concordance rates of the traditional, trimmed traditional and robust Youden charts are 87.1%, 92.9%, and 94.3%, respectively. Conclusions Among the three charts, the robust Youden chart presents the urea results best. [ABSTRACT FROM AUTHOR]

Ignition design of air injection wells is the crucial factor to a successful in-situ combustion. In this paper, experimental studies were carried out on post steam flooding wells at JIN-91 of Liaohe oilfield for improving ignition success rate. The experiments were conducted by a high temperature-pressure ignition device specifically designed for in-situ combustion, and the effects of various parameters were investigated by factorial experiments. The results showed that the ignition temperature was reduced and the ignition time was shortened due to three factors: heating temperature, reservoir pressure, and clay minerals. When heating temperature exceeded 360 °C, experimental pressure was higher than 4.0 MPa, and 10% of montmorillonite clay was added, the crude oil samples could be ignited rapidly. According to the factorial results, the most effective method to shorten ignition time is by increasing heating temperature, the safest method to reduce crude oil spontaneous combustion temperature and to shorten ignition time is by applying clay minerals, and reservoir pressure is the key factor for safety operation during ignition operation. These results will provide experimental theoretical guidance for high efficiency ignition, process optimization, and safe implementation of crude oil reservoir, they also will deliver tech support for the high efficiency operation of in-situ combustion. • The influence on pressure, heating temperature and clay minerals were analyzed. • The influence on the ignition process was conducted by factorial experiment. • One experimental device and test methods on ignition were developed for the first time. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we investigate the possibility to suppress interference in wideband multiple-input multiple-output radar. The idea is to employ tunable filters at the transmitter and the receiver sides, and to derive filter coefficients that result in optimal transmitted signals from a system performance point of view, for a given radar scenario. The system performance is measured in signal-to-interference-and-noise ratio (SINR) at the receiver output, from which the filter properties are derived. The focus is to suppress active jamming interference, and especially deceptive jamming interference. We discuss two ways to derive the transmit and the receive filters. Each procedure utilizes two different power constraints related to the transmit filters. To incorporate imperfections in the given scenario, a robust extension to the design problem is proposed. Two different robust methods are evaluated: one that utilizes a Taylor series expansion of the SINR, and one that exploits a worst-case SINR maximization. Numerical validation illustrates the possibility to suppress interference without actually forming a spatial null in the direction towards interference, and the necessity to design transmit filters that are robust to uncertainties in the given scenario. [Copyright &y& Elsevier]

Abstract: Analysis of Variance (ANOVA) separates the effects of different factors in a dataset. Typical examples for gene microarray data are the factors time and treatment. This separation can improve the interpretability of the results. However, the main effects and interactions, calculated in ANOVA, can be heavily influenced by outliers, large numbers of non-expressed genes with noise, and the heavy-tailedness of the distribution of expression values. Robust methods are less affected by these and will improve the analysis. In this paper, several methods to perform robust nonparametric ANOVA are applied to a large multi-treatment time series dataset. The results are compared with the results obtained with parametric ANOVA using Procrustes analysis. A further comparison is made by Gene Ontology (GO) enrichment analysis of groups of genes identified as significant by inspection of the interaction terms in ANOVA. It is shown that there are significant differences in the estimates of main effects and gene–treatment interactions. ROC curves show an improved representation of current biological knowledge for one particular robust form of ANOVA, using a combination of rank transformed data, with the median as location parameter. [Copyright &y& Elsevier]

Abstract: This paper investigates the development of Fault Detection and Isolation (FDI) filters for both retarded and neutral time-delay systems with unknown time-varying delays. Using a geometric framework, the notion of a finite unobservability subspace is introduced for time-delay systems and an algorithm for its construction is presented. A bank of residual generators is then designed so that each residual is affected by one fault and is partially decoupled from the others while the norm of the transfer function between the disturbances and the uncertainties in delays and the residuals are guaranteed to remain less than a prescribed value. Furthermore, it is shown that in the case of known delays it is possible to generate residuals that enjoy perfect decoupling properties among faults. Simulation results presented demonstrate the effectiveness of our proposed FDI algorithms. [Copyright &y& Elsevier]

Many real-world complex systems, such as power grids, the Internet, transportation networks, and complex information systems networks, which can be modeled abstractly with complex networks, may exhibit coupling or interdependence when subjected to random failure or deliberate attacks, i.e., cascading failures. Therefore, we want to understand the robustness of complex networks against cascading failures. The cascading failure has a failure propagation process, and it is necessary to establish an appropriate propagation model as the research basis. Hence, we adopted a new and more universal cascading failure propagation model based on discrete dynamic system. Based on this propagation model and combined with risk assessment, we proposed several cascading robustness index for complex networks. Then we conducted numerical experiments on several types of existing complex networks and real-world network. These experiments confirm the feasibility and rationality of our proposed indicators to reflect the cascading robustness, which can provide a reference and value for simulation and protection of real-world interdependent networks. [ABSTRACT FROM AUTHOR]

Abstract: Free-choice profile (FCP), developed in the 1980s, is a sensory analysis method that can be carried out by untrained panels. The participants need only to be able to use a scale and be consumers of the product under evaluation. The data are analysed by sophisticated statistical methodologies like Generalized Procrustean Analysis (GPA) or STATIS. To facilitate a wider use of the free-choice profiling procedure, different authors have advocated simpler methods based on principal components analysis (PCA) of merged data sets. The purpose of this work was to apply another easy procedure to this type of data by means of a robust PCA. The most important characteristic of the proposed method is that quality responsible managers could use this methodology without any scale evaluation. Only the free terms generated by the assessors are necessary to apply the script, thus avoiding the error associated with scale utilization by inexpert assessors. Also, it is possible to use the application with missing data and with differences in the assessors’ attendance at sessions. An example was performed to generate the descriptors from different orange juice types. The results were compared with the STATIS method and with the PCA on the merged data sets. The samples evaluated were fresh orange juices with differences in storage days and pasteurized, concentrated and orange nectar drinks from different brands. Eighteen assessors with a low-level training program were used in a six-session free-choice profile framework. The results proved that this script could be of use in marketing decisions and product quality program development. [Copyright &y& Elsevier]

Abstract: Multivariate methods based on curve resolution outperform single channel methods in the analysis of diffusion-ordered spectroscopy (DOSY) NMR data in terms of accuracy and ease of interpretation, especially for systems with large spectral overlap. In this paper, the focus is on the robustness of two multivariate methods, classical multivariate curve resolution (MCR) and MCR combined with non-linear least squares regression (MCR–NLR). Three important factors that influence the analysis are investigated: Peak shifts, phase shifts, and the difference of diffusion coefficients. Using controlled disturbances of a data set of a mixture of three discrete components, ATP, glucose, and SDS, it is shown that both multivariate methods outperform SPLMOD, one of the standard single channel methods. In particular, MCR–NLR is the more accurate as well as the more robust of the two multivariate methods. This implies that MCR–NLR is less sensitive to the quality of the data and may give good results in cases where other methods fail. [Copyright &y& Elsevier]

Abstract: Clinical trial AIN503/A5217 investigates whether a period of early treatment with antiretroviral therapy might lower the viral setpoint in subjects recently infected with HIV-1. We consider two statistical issues. First, even under the null hypothesis control arm subjects are more likely than treatment arm subjects to be missing final outcome data because of disease progression. The analysis must adjust for this missing data, or it may be unacceptably biased. Second, comparing outcomes between treatment and control arms at identical times post-randomization gives different information than comparing outcomes at the same amount of time off-therapy, as measured post-randomization. This may make interpretation of results problematic. We formulate the null hypothesis of the study as exchangeability under a time-shift between arms, which we call “time delay” between the study arms. This captures clinically relevant information, and allows us to formalize a two-stage hypothesis test in which stage one is a comparison between arms at identical times post-randomization, and stage two is a comparison between arms at identical times off-therapy, as measured post-randomization. Importantly, within this framework we can show that the two-stage test can be adjusted for the missing data using a simple worst-rank substitution. [Copyright &y& Elsevier]

Abstract: We describe techniques for the application of two methods, robust to the presence of ‘outliers’, to the hierarchical analysis of variance of bacterial count data from collaborative trials. The techniques are tested against both artificially-generated data with known distributional parameters and actual trial results containing outliers. The relative merits of the robust methods are discussed in comparison with conventional ANOVA techniques. [Copyright &y& Elsevier]

The proposed algorithm of extended predictive control (EPC) represents an exact method for removing the ill-conditioning in the system matrix by developing a unique weighting structure for any control horizon. The main feature of the EPC algorithm is that it uses the condition number of the system matrix to evaluate a single tuning parameter that provides a specified closed-loop response. Robust analysis demonstrated that EPC is more robust in comparison with move-suppressed and m-shifted predictive controllers in all aspects of process variation in gain, delay, and time-constant ratios. Tuning of EPC is effective and simple since there is a direct relationship between closed-loop performance and its tuning parameter. [ABSTRACT FROM AUTHOR]

Abstract: A dielectric barrier discharge (DBD) plasma, operating in air at atmospheric pressure, has been used to induce changes in the surface properties of polyethylene terephthalate (PET) films. The effects that the key DBD operating parameters: discharge power, processing speed, processing duration, and electrode configurations, have on producing wettability changes in the PET surface region have been investigated. The approach taken involves the application of an Taguchi experimental design and robust analysis methodology. The various data sets obtained from these analyses have been used to studies the effect of the operating parameters on the surface uniformity and efficiency of the said treatment. In general, the results obtained indicate that DBD plasma processing is an effective method for the controlled surface modification of PET. Relatively short exposures to the atmospheric pressure discharge produces significant wettability changes at the polymer film surface, as indicted by pronounced reductions in the water contact angle measured. It was observed that the wettability of the resultant surface shows no significant differences in respect to orientation parallel (L-direction) or perpendicular (T-direction) to the electrode long axis. However, there was significant differences between the data obtained from these two orientations. Analysis of the role of each of the operating parameters concerned shows that they have a selective effectiveness with respect to resultant surface modification in terms of uniformity of modification and wettability. The number of treatment cycles and the electrode configuration used were found to have the most significant effects on the homogeneity of the resultant PET surface changes in L- and T-orientation, respectively. On the other hand, the applied power showed no significant role in this regard. The number of treatment cycles was found to be the dominant factor (at significance level of 0.05) in respect of water contact angle changes at the processed PET surface in both orientations. The driven metal electrodes (stainless steel or aluminium) were apparently superior to the driven dielectric electrode (ceramic or quartz) configurations. The grounded electrode in each case was a silicon rubber-covered aluminium plate (see later). The nature and scale of the surface changes that originate from the various processing conditions employed have been considered so as to determine the optimum treatment conditions in respect of processing outcomes, properties and any orientation dependence. Thus, it was revealed that higher processing speeds and longer processing durations are key for uniformity along the electrode axial orientation, while lower processing speeds and short exposure durations are key considerations, in the corresponding perpendicular orientation. In general, longer processing durations (low processing speeds and a high number of treatment cycles) and higher plasma powers induced greater changes in the surface wettability of the PET, as demonstrated by the observed water contact angles. This behaviour is taken to indicate that different combinations of DBD operating parameters and electrodes produce discharge conditions that can result in different plasma chemical processes in respect of uniformity, treatment efficiency and orientation dependence. [Copyright &y& Elsevier]

Nowadays under COVID 2019, e-learning has become a potential prop approach of technology in education that provides contemporary learners with authentic knowledge acquisitions. As a practical contribution, electronic examination (e-exam) is a novel approach in e-learning designed to solve traditional examination issues. It is a combination of assorted questions designed by specialized software to detect an individual's performance. Despite intensive research in this area, the performance of e-exams faces challenges such as authentication of the examinee's identity and answered papers. This paper aims to present the experiences of educational organizations in e-exam and e-evaluation as an essential tool of e-learning in various countries. The paper recommends that under the global pandemic COVID 2019 evaluating students using intensive continuous evaluation, including e-exam supported by authentication methods, which may help detect and reduce or even prevent student violations. The results show that the most used LMS tools were the Moodle and proprietary solutions which were 75% both among many other LMS tools i.e., Blackboard and eFront. The least develop countries are prefer to use open source and proprietary due to the zero cost of these solutions. The internet speed, cost and authenticity were the most challenges faced e-exams centers, which were 99%, 82%, and 68%, respectively. [ABSTRACT FROM AUTHOR]

• We can precisely predict the impacting location, time and rebound velocity for a two-dimensional frictional system involving impacting by using analytical solutions. • We propose a new numerical algorithm for the numerical solution of a two-dimensional frictional system involving impacting. • We select several representative scenarios to evaluate and verify the accuracy and robustness of the new algorithm in a two-dimensional frictional system with boundaries. • The relative errors of impacting locations are insensitive to the boundary complexity by utilizing our proposed algorithm. • Our new algorithm is better than two conventional methods in calculating impacting location and time with high accuracy. Impacting and friction are always encountered in the mechanical system and make the system experience nonlinearities in both force-position and force-velocity characteristics. In this paper, we propose one effective numerical algorithm for a two-dimensional frictional system involving the impacting by employing the closed form solution to yield the slip responses and extend the closed form solutions for curve length to predict the impacting location and time with high accuracy. By performing the accuracy analysis and robustness analysis through several representative scenarios, we reveal that, (1) the impacting dynamic responses can be predicted through our new algorithm with high accuracy, (2) the accumulative errors of dynamic responses are insensitive to the complex boundary, (3) the new algorithm can keep better robustness when involving repeated impacting. [ABSTRACT FROM AUTHOR]