Observation Interval Research Articles

Interval observer-based consensus tracking for multi-agent systems under Markovian switching topologies with stealthy attack

This article investigates the bounded consensus tracking problem for uncertain linear multi-agent systems (MASs) under Markovian switching topologies in the presence of unknown but bounded disturbances and stealthy attacks. First, a class of interval observers (IOs) is designed to estimate confidence bounds of agents states and stealthy attack signals. The stealthy attack is considered as that the output information is modified by the malicious attacker. Second, distributed control protocols under Markovian switching topologies are proposed for the MASs based on the designed IOs to achieve bounded consensus. The mean-square error bounds depend on the error bounds of disturbances. After rigorous mathematical proofs, some sufficient conditions are acquired for achieving control goals. Simulations are provided to validate the effectiveness of the proposed IOs and control protocols.

Respiratory manifestations of pediatric granulomatosis with polyangiitis: A 12-year experience from a tertiary care facility.

Pediatric granulomatosis with polyangiitis (GPA) is associated with several pulmonary manifestations. This study aims to describe these manifestations at time of diagnosis and longitudinally at a tertiary-care pediatric hospital. We performed a retrospective chart review of patients with GPA treated at our facility between 1 January 2010 through 31 December 2021. We collected baseline demographics, reported symptoms, imaging findings, pulmonary function tests (PFTs), and laboratory data at time of diagnosis. Data were collected using 6-month observation intervals to follow recurrence of respiratory manifestations, testing during recurrence, and resultant treatment modifications. Of 13 patients treated for GPA during the study period, 12 developed respiratory tract involvement. A total of 87 6-month observation periods were analyzed. At time of diagnosis, 83% (10/12) of subjects reported respiratory symptoms, 92% (11/12) had abnormal chest computed tomography (CT) imaging, and 42% (5/12) had abnormal PFTs. Fewer than half of the patients were seen by pulmonology within 6 months of diagnosis. Eight subjects (75%) had respiratory manifestations during subsequent observation periods. Chest CT or PFTs were obtained in 23/44 (52%) of observations periods with respiratory symptoms, with pulmonary consultation in only 9/44 (20%). This is the first US study to describe respiratory manifestations in pediatric GPA patients longitudinally, finding they are common and frequently recurrent. Our cohort had almost universally abnormal imaging at diagnosis regardless of respiratory symptoms. Early collaboration with pediatric pulmonology in the care of GPA patients may allow rheumatology teams to efficiently evaluate recurrent symptoms and address concomitant lung disease.

Incidence of Concurrent Cerebral Desaturation and Electroencephalographic Burst Suppression in Cardiac Surgery Patients.

Increased intraoperative electroencephalographic (EEG) burst suppression is associated with postoperative delirium. Cerebral desaturation is considered as one of the factors associated with burst suppression. Our study investigates the association between cerebral desaturation and burst suppression by analyzing their concurrence. Additionally, we aim to examine their association with cardiac surgical phases to identify potential for targeted interventions. We retrospectively analyzed intraoperative 1-minute interval observations in 51 patients undergoing cardiac surgery. Processed EEG and cerebral oximetry were collected, with the anesthesiologists blinded to the information. The associations between cerebral desaturation (defined as a 10% decrease from baseline) and burst suppression, as well as with phase of cardiac surgery, were analyzed using the Generalized Logistic Mixed Effect Model. The results were presented as odds ratio and 95% confidence intervals (CIs). A value of P < .05 was considered statistically significant. The odds of burst suppression increased 1.5 times with cerebral desaturation (odds ratio [OR], 1.52, 95% CI, 1.11-2.07; P = .009). Compared to precardiopulmonary bypass (pre-CPB), the odds of cerebral desaturation were notably higher during CPB (OR, 22.1, 95% CI, 12.4-39.2; P < .001) and post-CPB (OR, 18.2, 95% CI, 12.2-27.3; P < .001). However, the odds of burst suppression were lower during post-CPB (OR, 0.69, 95% CI, 0.59-0.81; P < .001) compared to pre-CPB. Compared to pre-CPB, the odds of concurrent cerebral desaturation and burst suppression were notably higher during CPB (OR, 52.3, 95% CI, 19.5-140; P < .001) and post-CPB (OR, 12.7, 95% CI, 6.39-25.2; P < .001). During CPB, the odds of cerebral desaturation (OR, 6.59, 95% CI, 3.62-12; P < .001) and concurrent cerebral desaturation and burst suppression (OR, 10, 95% CI, 4.01-25.1; P < .001) were higher in the period between removal of aortic cross-clamp and end of CPB. During the entire surgery, the odds of burst suppression increased 8 times with higher inhalational anesthesia concentration (OR, 7.81, 95% CI, 6.26-9.74; P < .001 per 0.1% increase). Cerebral desaturation is associated with intraoperative burst suppression during cardiac surgery, most significantly during CPB, especially during the period between the removal of the aortic cross-clamp and end of CPB. Further exploration with simultaneous cerebral oximetry and EEG monitoring is required to determine the causes of burst suppression. Targeted interventions to address cerebral desaturation may assist in mitigating burst suppression and consequently enhance postoperative cognitive function.

Method for Detecting Fire Indoors Based on Differences in Sample Averages of an Arbitrary Gas Environment Dangerous Parameter at Adjacent Observation Intervals

The object of the research is the series average of the dangerous parameters of the gas environment during the ignition of materials. The practical importance consists of using the difference between the average dangerous parameters of the gas environment on the intervals of absence and the presence of ignition to detect the ignition of materials. The theoretical substantiation of the method of detecting fires in premises is carried out based on sample averages fixed samples of current measurements of an arbitrary, dangerous parameter of the gas environment, which correspond to the general population of reliable absence and presence of fire. At a given significance level, the method determines the unbiased, uniformly most powerful fire detection rule. This allows you to determine how significant differences in sample means with a given significance level are due to ignition or are random. Laboratory experiments were conducted to verify the method of detecting the ignition of test materials. It was established, for example, that the maximum size of the effect ignition on the carbon monoxide concentration is typical for alcohol (exceeds the threshold by 8.9 times) and textiles (exceeds the threshold by 9.3 times). The size of the effect of the smoke density upon ignition of all materials is approximately the same and is determined by exceeding the corresponding thresholds from 4.62 to 3.9 times. The size of the effect on the temperature of the gaseous environment during ignition of all test materials is approximately the same order. It is characterized by exceeding the corresponding thresholds from 5.95 to 3.58 times. It is shown that the method of detecting fires allows to establish the extent to which the detected differences in sample means for samples from the general population of hazardous parameters of the gas environment are reliable with a given level of significance and are due to the ignition of materials or the action of random factors.

Study on the neurotoxicity of the temephos impregnated kenaf cellulose nanofiber (KCNF+T) aerosols against the female Aedes aegypti mosquitoes.

The study has generated visible aerosols with the diameter of 11 to 35 µm from the kenaf cellulose nanofiber (KCNF) impregnated with the temephos (KCNF+T) in water suspension. The study aimed to determine whether the KCNF+T aerosols are capable to elicit neurotoxicity in the adult mosquitoes via the respiratory exposure route by observing their behavioural response and measuring its body acetylcholine esterase (AChE) activity. Adult Aedes aegypti mosquitoes were assigned to one negative control group and three treatment groups namely, distilled water (vehicle control), KCNF and KCNF+T. The study adopted the MS1911 whereby the aerosols generated are released into the insecticide bioassay glass chamber (IBGC) separately to achieve four different aerosols concentrations of 6.4 ml/m3, 12.8 ml/m3, 19.2 ml/m3, and 25.6 ml/m3. Then the 20 sugar-fed mosquitoes were released free-flying into each IBGC to observe its behavioural response (knockdown) at 30, 60, 120, 180, 240, 300 minutes intervals and 24th hour mortality. Results showed that only mosquitoes exposed to KCNF+T aerosols exhibited persistent knockdown. There was significant difference (p< 0.05) between observation intervals with the cumulative knockdown of 84.8%, 92.8%, 99.0%, 100.0%, 100.0%, 100.0% compared with the KCNF aerosols. Further, it was distinctive that only KCNF+T is capable to cause the female mosquitoes moribund/mortality at the 24th hour with 90% at the lowest aerosol concentration of 6.4 ml/m3. The neuroenzyme assay on the mosquito that died from the KCNF+T exposure verified to have reduced AChE enzyme activity. The behavioural response and reduction of the AChE activity strongly suggests the temephos from the KCNF+T aerosols has been released into the mosquito body causing the neurotoxicity but KCNF alone is not neurotoxic.

A longitudinal 5-year study for the prediction of HCC, death and liver decompensation by ARFI elastography.

Numerous studies have evaluated elastography for the staging of liver fibrosis. Fewer studies were performed investigating the prognostic relevance using transient elastography (TE), although with promising results. This study was designed to evaluate the prognostic relevance of ARFI elastography. Patients receiving ARFI elastography in our ultrasound department between 2010 and 2012 were initially screened for an ARFI examination with a clinical follow-up of at least 5 years. The following events were recorded: liver related death, liver unrelated death, HCC, liver decompensation/ variceal bleeding. A total of 335 patients were included in the final analysis with an ARFI examination of the liver and a follow-up of 60 months. Within the observation interval the number of events with corresponding AUROCs (shown with 95% confidence interval) were: overall death (n=49, 0.76 [0.69 - 0.83]), liver related death (n=25, 0.85 [0.77 - 0.93]), liver unrelated death (n=24, 0.66 [0.55 - 0.77]), HCC (n=15, 0.80 [0.72 - 0.87]), liver related complications/variceal bleeding (n=34, 0.87 [0.82 - 0.93]). In the group of patients with ARFI values suggestive of cirrhosis (equal to or above 1.80 m/s; n=110) higher values (<2.5 m/s vs. >= 2.5 m/s) where associated with a significant decline in liver related survival (p=0.007). ARFI elastography seems to have a good diagnostic accuracy for the prediction of liver related death and decompensation. Further it seems to allow a risk stratification in patients with cirrhosis suspicious elastography values.

Interval State Estimation of Systems with Metzler Polytopic Models

The paper deals with the design of interval observers for interval-defined strictly Metzler polytopic positive systems. The stability conditions for the proposed structure of the interval observer are formulated using linear matrix inequalities to ensure a positive estimate of the system state. The proposed method makes it possible to calculate time-varying lower and upper estimates of the state vector, assuming that the disturbance is bounded. Finally, a numerical example is given to illustrate the effectiveness of the proposed method.

Interval observers for hybrid continuous-time stationary systems

The problem of interval observer design for hybrid continuous-time stationary systems under external disturbances and measurement noise is studied. It is assumed that continuous-time dynamic of such systems is described by linear or nonlinear differential state equations with linear function of output. System parameters depend on system states and are switched based on the control system with finite set of states. The relations allowing designing hybrid interval observer of minimal dimension estimating the set of admissible values of the prescribed linear vector function of the system states are derived. To solve the problem, algebra of partitions and linear algebra are used. Theoretical results are illustrated by example.

A dynamic evaluation of an underground transportation system using image processing and centrality index computation

ABSTRACT The study of transportation networks covers a wide range of topics related to managing services and maintaining structures. In order to represent the topological structure of such a network, we associated a graph to a network. Then some different properties or attributes of the network can be managed as weights to be applied to the graph itself. In addition, different centrality indices can be computed in order to identify nodes or edges that are more important or more exposed to capacity changes (such as, for example, disruptive events). The purpose of this research is to provide a methodology for dynamically evaluating the significance of stations in a transportation network. This is accomplished through two distinct phases of activity. Firstly, we propose a dynamic analysis of the underground transportation system of the city of Milan, Italy. This transportation system is the mobility backbone of the city and counts four lines with 110 links and 107 stations, including 21 junctions (the transfer stations that connect the lines). Two data sets about passenger flows (both entering and leaving stations) are used to calculate the flows on links with a resolution of 1 min. The data sets refer to a week in 2018, without the changes in demand due to the pandemic scenario. Data are processed through an ad hoc written assignment procedure. Secondly, a centrality index is calculated by using passenger flows (entering, exiting, and on-segments) as weights of the underground graph. After maps reporting the outcomes of those calculations are drawn, an image comparison is carried out by using image processing tools and different aggregation intervals, in order to investigate how the importance or exposure of each station changes over time. The findings demonstrate that over time, indices vary by station, with junction stations naturally having the highest values. By increasing the observation interval from 1 min up to 30 min, index changes become progressively smoother, like an application of a low pass filter, suggesting that for certain applications (e.g. those concerning security), aggregating data could lead to misleading conclusions.

Improved functional interval observer for mecanum‐wheels omnidirectional automated guided vehicle

AbstractThis article presents a study of interval estimation approach based on functional interval observers for mecanum‐wheels omnidirectional automated guided vehicle (MOAGV). In the context of MOAGV, the nonlinear system in discrete time incorporates model uncertainty and unknown bounded disturbances. A functional observer is developed by integrating terminal sliding mode and techniques, aiming to reduce the impact of lumped disturbances/uncertainties. Additionally, a novel observer structure is introduced to increase the degrees of freedom in the design process. Subsequently, the linear function bounds are obtained using the reachability analysis of the estimation error. Finally, the performance of the improved functional interval observer is demonstrated by numerical simulations.

347 Quantifying phenotypic and genetic variation for cow fertility phenotypes in American Simmentals using total herd reporting data

Abstract Inefficiencies in reproduction are the largest drivers of loss in United States beef production. Nearly all reproductive traits are at least modestly heritable, making genetic selection and improvement possible over the long term. Cow-centric reproductive traits present unique challenges, as they are not expressed in male animals and will not be observed until later in the productive life of a female, if at all. This makes cow-centric fertility traits ideal candidates for selection with Expected Progeny Differences (EPDs). We used a commercially generated dataset from the American Simmental Association (ASA) to explore the phenotypic and genetic variation in these traits. The dataset comprised Total Herd Enrollment (THE) records, which required unbiased reporting of enrollment, calving, and disposal for 303,158 females (132,403 cows and 170,755 heifers). Using the THE data, we calculated three continuous and two discrete traits that are indicators of heifer and cow fertility and rebreeding ability. These traits were: 1) calving date (calving date of the cow relative to the start of the calving season), 2) calving interval (days between calves), 3) first calving interval (calving interval observation between the first and second calving record for a female), 4) heifer pregnancy (did the animal calve as 2-yr-old?), and 5) discrete early calving (did animal calve in the first 30 d of the calving season?). We observed a significant difference in calving date in mature cows that calved in the first 30 d of the calving season of their contemporary group as heifers compared with those that calved later (Table 1). Early calving heifers averaged a nearly 10 d sooner calving date throughout their productive lives compared with those that calved after 30 d as heifers (29.9 d vs. 40.2 d, P-value &amp;lt; 0.01). We used a combined pedigree and genomic approach, implemented in GIBBSF90+, to estimate genetic, environmental, and permanent environmental variance components. We estimated heritabilities of 0.24 (± 0.037215) for heifer pregnancy, 0.06 (± 0.009265) for calving date, 0.07 (± 0.015451) for discrete early calving, 0.04 (± 0.003954) for calving interval, and 0.04 (± 0.009604) for first calving interval. We observed positive phenotypic and genetic correlations between these traits, ranging from 0.01 to 0.96 (Table 2). This work provides an extensive population survey of phenotypic trends in reproductive performance and management in a large seedstock population. The heritable nature of the inspected traits motivates further work in understanding their genetic architectures and how they are affected by heterosis in crossbreeding programs.

Generalized Time‐Series Analysis for In Situ Spacecraft Observations: Anomaly Detection and Data Prioritization Using Principal Components Analysis and Unsupervised Clustering

AbstractIn situ spacecraft observations are critical to our study and understanding of the various phenomena that couple mass, momentum, and energy throughout near‐Earth space and beyond. However, on‐orbit telemetry constraints can severely limit the capability of spacecraft to transmit high‐cadence data, and missions are often only able to telemeter a small percentage of their captured data at full rate. This presents a programmatic need to prioritize intervals with the highest probability of enabling the mission's science goals. Larger missions such as the Magnetospheric Multiscale mission (MMS) aim to solve this problem with a Scientist‐In‐The‐Loop (SITL), where a domain expert flags intervals of time with potentially interesting data for high‐cadence data downlink and subsequent study. Although suitable for some missions, the SITL solution is not always feasible, especially for low‐cost missions such as CubeSats and NanoSats. This manuscript presents a generalizable method for the detection of anomalous data points in spacecraft observations, enabling rapid data prioritization without substantial computational overhead or the need for additional infrastructure on the ground. Specifically, Principal Components Analysis and One‐Class Support Vector Machines are used to generate an alternative representation of the data and provide an indication, for each point, of the data's potential for scientific utility. The technique's performance and generalizability is demonstrated through application to intervals of observations, including magnetic field data and plasma moments, from the CASSIOPE e‐POP/Swarm‐Echo and MMS missions.

Do early midlife work characteristics predict 20-year change in control beliefs?

Previous research showed the importance of control beliefs for many life outcomes. The present study examines associations between subjectively perceived work environment and objectively measured work activities at the beginning of midlife as a central developmental phase in the context of work, with control beliefs across the subsequent 20 years. We analyzed four-wave longitudinal data from N = 374 participants (born 1950-1952; Mage baseline = 44 years, SD = 1; 44% women) from the Interdisciplinary Longitudinal Study of Adult Development and Aging within a structural equation modeling framework. Over 20 years and overall, internal control beliefs were stable, while external control beliefs decreased. Individuals who reported higher task variety and better social integration at work at baseline also reported higher levels of control beliefs for positive life outcomes. In addition, higher social integration at work at baseline was related to lower levels of external control beliefs. Work characteristics at baseline were not associated with individual differences in change in control beliefs across the 20-year observational interval. In summary, our findings suggest that work experiences at the prime of job-related development around the midst of the fifth decade of life do not play a major role in subsequent control beliefs development across 20 years. However, investigations measuring control beliefs as well as work characteristics continuously over a long period of time are necessary to shed light on reciprocal influences between work and personality. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Beta-blockers and their impact on metabolic processes

The aim of the study is to determine the effect of beta-blockers on lipid status, triglycerides and Body Mass Index (BMI) in patients using beta-blockers in the treatment of arterial hypertension. Our study included 120 patients at the Public Health Institution "Dom zdravlja" Živinice. The participants were monitored over a period of 3 years. Measurements were made after 12, 24 and 36 months of treatment. Patients were divided into two groups. The experimental group included 60 patients, who used beta-blockers in the treatment of arterial hypertension. The control group included 60 patients who used other antihypertensives as their first choice medication in the treatment of arterial hypertension. By monitoring cholesterol and triglyceride levels in patients using beta-blockers and other antihypertensive medications, and comparing these values within the group, no statistically significant difference in cholesterol and triglyceride levels was found in patients who used beta-blockers after 12, 24, and 36 months of treatment. There was also no statistically significant effect of therapy on the change in cholesterol and triglyceride values at observed time intervals, nor was there a statistically significant difference between these values. BMI monitoring showed a statistically significant difference between patients using beta-blockers and other antihypertensive drugs, with patients using beta-blockers having a higher BMI after 36 months of treatment. There was no statistically significant difference in BMI between patients using bisoprolol and carvedilol and patients using other beta-blockers, but patients using bisoprolol and carvedilol had lower BMI values. In studies conducted in recent years, it has been noted that many beta-blockers cause dose-dependent adverse metabolic effects on glucose and lipid metabolism, with the most adverse metabolic effects observed in patients treated with conventional non-selective beta-blockers. On the other hand, more favorable metabolic profile have drugs with β1 selective activity, such as atenolol and metoprolol, especially those with intrinsic sympathomimetic activity such as pindolol. In fact, with these beta-blockers, the adverse metabolic effects appear to be less prominent. In conclusion, beta-blockers do not lead to an increase in cholesterol and triglycerides, but they do lead to an increase in BMI in patients with arterial hypertension

Maximum likelihood estimation for multi-factor uncertain differential equations

Multi-factor uncertain differential equation (MUDE) is widely used in dynamic systems with multiple types of uncertainties. After observing actual data, how to estimate unknown parameters based on these observations rationally is a key issue. Existing estimation methods are based on difference scheme of MUDE with a prerequisite that observation intervals are small enough. To overcome this shortage, a novel maximum likelihood method is proposed using the concept of residual for MUDE in this work. Both analytical and numerical methods for calculating residuals are also studied. In addition, uncertain hypothesis test is employed to verify the reasonableness of estimations. Numerical example and real data analyses show the proposed method in details.

Bleeding us dry: The financial impact of full blood examinations in the immediate postoperative period.

Full blood examinations, often referred to as FBE, are commonly ordered postoperatively, despite limited utility in many of its markers in the acute phase. It is estimated that in the 2022-2023 financial year, the Australian healthcare system billed over $13 million for full blood examinations (FBEs) to Medicare. This study aims to assess the cost of using FBE following surgery. We explore potential cost savings by using a haemoglobin examination (HE) in replace of FBE, with both tests run on identical machines, producing the same result, but at a fraction of the cost. A retrospective analysis was conducted at a single institution, including all patients who underwent minimally invasive laparoscopic pelvic surgeries between 1/7/2017 and 30/6/2019. Patient records were examined to identify patient demographics, postoperative pathology tests and interventions. Patients who received FBE in the first 24 h following surgery were identified and included in the study. Using national surgery and admission statistics, a potential cost-saving analysis will be performed. Among 519 men who underwent robotic-assisted pelvic surgery, 325 patients had routine postoperative investigations, with 323 receiving FBE and 2 receiving HE. Abnormal results were found in the majority of patients that underwent FBE. Eight patients received packed red blood cell transfusion, none of these meeting the hospital-specific criteria for transfusion protocol. Twelve patients received antibiotics, none were in response to abnormal FBE, with all patients experiencing a fever, given prophylactically or in the days following the surgery. FBE and HE are both listed on the Medicare Benefits Scheme at $16.95 and $7.85, respectively, the difference being $9.10. Extrapolating the existing data, within the first 24 h following surgery, the estimated savings were $8818, with savings increasing accumulatively with longer observation intervals following surgery. When similar savings are applied to national figures, the potential savings to the Australian Public Healthcare system likely exceeds millions. Our study revealed that over half of the patients who underwent a RARP received FBE within the first 24 h postoperatively, the vast majority of which exhibited abnormal results that were not acted upon. These findings substantiate the limited utility of FBE in the postoperative setting. Cell markers observed in FBE are predominantly subjective, but consensus exists regarding the importance of evaluating haemoglobin levels postoperatively. Considering that one in four hospital admissions involves surgical procedures, and a $9.10 price differential between FBE and HE, the potential annual economic impact of utilising routine FBEs for assessing haemoglobin levels immediately after surgery is likely to reach millions. Although having obvious flaws, these results underscore the potential accumulative cost arising from everyday clinical judgement and the importance of thoughtful consideration when ordering pathology. The routine ordering of FBE postoperatively, without properly considering its indication, incurs significant costs. This study highlights the potential cost savings by HE instead, emphasising the need for revaluation and appropriate utilisation of pathology tests in the immediate postoperative period given the physiological acute phase response expected postoperatively.

Energy Efficiency for Faster-than-Nyquist Data Transmission Using Processing Algorithms with Decision Feedback

One of the ways to increase the volume of transmitted information is to increase the bit rate above the Nyquist barrier. However, an increase in bit rate in the case of FTN (Faster-Than-Nyquist) signals leads to an increase in energy costs for receiving information on channels with limited bandwidth, for example, in Digital Video Broadcasting satellite systems like DVB-S2/S2X. It is possible to minimize energy losses by using the processing algorithm “maximum likelihood sequence estimation”. However, the computational complexity of this algorithm is extremely high, which limits its use, especially in terrestrial mobile satellite terminals. We propose a new bit-by-bit decision feedback algorithm with maximum likelihood ratio estimation of subsequent symbols in the observation interval. This algorithm provides minimal energy costs comparable to the method “maximum likelihood sequence estimation” at speeds 2–3 times higher than the Nyquist barrier. At the same time, the complexity is two orders of magnitude less. It is shown by simulation for a channel with additive noise that energy losses in relation to the potential bit error rate (BER) are less than 4.5 dB. In the presence of Rayleigh fading, the application of the proposed algorithm makes it possible to provide the processing of FTN signals for double bit rates in urban areas with energy costs equal to 12 dB when using an equalizer. We give numerical estimations of the increase in computational complexity for the proposed processing algorithm. It is shown that an increase in the bit rate by 1.5 times leads to an increase in the computational complexity by more than an order of magnitude. The same conclusion can be reformulated in another form: for the proposed algorithm, each decibel of energy gain is achieved by increasing the number of computational operations by 1.5×105. It is experimentally shown that additional energy losses due to non-ideal phase and timing synchronization are no more than 1 dB when the proposed algorithm is applied in a fading channel. The energy costs in fading channels relative to a stationary channel for twice the Nyquist rate are equal to 13.8 dB when using an equalizer.

Human-in-the-Loop Consensus Control for Multiagent Systems With External Disturbances.

In this article, the human-in-the-loop leader-follower consensus control problem is addressed for multiagent systems (MASs) with unknown external disturbances. A human operator is deployed to monitor the MASs' team by transmitting an execution signal to a nonautonomous leader in response to any hazard detected, with the control input of the leader unknown to all followers. For each follower, a full-order observer, in which the observer error dynamic system decouples the unknown disturbance input, is designed for asymptotic state estimation. Then, an interval observer is constructed for the consensus error dynamic system, where the unknown disturbances and control inputs of its neighbors and its disturbance are treated as unknown inputs (UIs). To process the UIs, a new asymptotic algebraic UI reconstruction (UIR) scheme is proposed based on the interval observer, and one of the significant features of the UIR is the capacity to decouple the control input of the follower. The subsequent human-in-the-loop asymptotic convergence consensus protocol is developed by applying an observer-based distributed control strategy. Finally, the proposed control scheme is validated through two simulation examples.

Interval Observers for Estimating Unknown Inputs in Discrete Time-Invariant Dynamic Systems

This paper considers discrete time-invariant systems (with constant parameters) described by dynamic models in the presence of exogenous disturbances. For such systems, the problem of estimating unknown inputs using interval observers is studied. The solution is based on a minimal-dimension disturbance-insensitive model of the original system. For this model, an interval observer is designed and then used to estimate the unknown inputs. The theoretical results are illustrated with a practical example.

Statistical inference for innovation distribution in ARMA and multi-step-ahead prediction via empirical process

The kernel distribution estimator (KDE) is proposed based on residuals of the innovation distribution in the autoregressive moving-average (ARMA) time series. The deviation between KDE and the innovation distribution function is shown to converge to the Brownian bridge, leading to the construction of a Kolmogorov–Smirnov smooth simultaneous confidence band for the innovation distribution function. Additionally, an empirical cumulative distribution function (CDF) based on prediction residuals is introduced for the multi-step-ahead prediction error distribution function. This empirical process weakly converges to a Gaussian process with a specific covariance function. Furthermore, a quantile estimator is derived from the empirical CDF of prediction residuals, and multi-step-ahead prediction intervals (PIs) for future observations are established using these estimated quantiles. The PIs achieve the nominal prediction level asymptotically for the finite variance ARMA model. Simulation studies and analysis of crude oil price data confirm the validity of the asymptotic theory.