Miracle-dz/UniFAR-FTUs huggingface dataset:
Dissipativity theory for hybrid systems with applications to networked control systems

by Michael J. McCourt This dissertation provides new results for energy-based analysis of systems modeled by switched or hybrid system models. This work is motivated by applications in cyber physical systems where systems evolve according to a combination of physical dynamics and cyber, event-driven dynamics. Having a combination of physical and logical dynamics, cyber physical systems are best modeled using switched or hybrid models. The original energy-based results presented here are based on the notions of passivity and dissipativity from classical nonlinear control theory. Existing theory provides valuable results for analyzing stability for interconnected systems. These methods are well established for nonlinear dynamical systems but do not directly apply to more general system models. A main goal of this dissertation is to provide generalizations of these concepts for hybrid systems. This includes an original definition of passivity indices for switched systems in Chapter 4 and notions of supervisory control using passivity indices in Chapter 6. It also includes original definitions of dissipativity for discrete-event systems and hybrid systems in Chapters 7 and 8. While these properties are useful in practice, they are often difficult to show. Chapter 10 covers computational methods of demonstrating passivity for switched systems. Often cyber physical systems are built up by connecting components over existing
Uncovering individual's mobility patterns from GPS dataset

Human mobility patterns, including issues such as locations of significance, modes of transport, trajectory patterns, location-based activities, are of great importance to a wide range of research areas and location-related applications. Based on the patterns uncovered, various mobility models may be proposed to predict individual’s future whereabouts, or to evaluate the protocols for wireless communications, among other applications. In this thesis, I present a study of individual’s mobility patterns based on GPS records. The study in this thesis includes inferring the modes of transport, analyzing the predictability of individual’s mobility, constructing mobility model, and predicting future locations. Modes of transport, such as walking, biking, driving, or taking a bus, are a basic pattern of individual’s mobility. Current studies on inferring the modes of transport apply supervised methods, which include a tedious training process. In this thesis, I present an unsupervised method for inferring the modes of transport, which eliminates the need of manual labeling and training while attaining equal or greater accuracy compared to the best known supervised method. The unsupervised method relies on Kolmogorov-Smirnov Test which offers a theoretical assurance when comparing segments of records. Various probabilistic models and algorithms, such as Markov models, Bayes models, pattern mining methods, have been proposed to predict individual’s next moves. The predicting accuracy has been greatly improved because of these efforts. However, little is known whether the predicting accuracy is already approaching the limit and hence further research efforts may yield diminishing returns. Moreover, the predicting accuracy is apparently affected by the scale of the places visited and the time interval concerned. In this thesis, I present a study of the predictability of individual’s mobility sequences. The predictability quantifies the potential to foresee the next moves of an individual based on his/her historical records. Using high-resolution GPS data, the scaling effects on predictability are investigated. Given specified spatio-temporal scales, recorded trajectories are encoded into long strings of distinct locations, and several information-theoretic measures of predictability are derived. I show that high predictability is still present at rather high spatial/temporal resolutions. The predictability is found to be independent of the overall mobility area covered, which suggests highly regular mobility behaviors. Moreover, by varying the scales over a wide range, an invariance between the predicting accuracy and spatial resolution is observed which suggests that certain trade-offs between these two are unavoidable.
On Optimal Point and Block Prediction in Log‐Gaussian Random Fields

Abstract. This work discusses the problems of point and block prediction in log‐Gaussian random fields with unknown mean. New point and block predictors are derived that are optimal in mean squared error sense within certain families of predictors that contain the corresponding lognormal kriging point and block predictors, as well as a block predictor originally motivated under the assumption of ‘preservation of lognormality’, and hence improve upon them. A comparison between the optimal, lognormal kriging and best linear unbiased predictors is provided, as well as between the two new block predictors. Somewhat surprisingly, it is shown that the corresponding optimal and lognormal kriging predictors are almost identical under most scenarios. It is also shown that one of the new block predictors is uniformly better than the other.
What`s fair is fair

The newly elucidated strategy for the magnetic fusion program set forth by the Department of Energy calls for increased emphasis on alternate concepts. This strategy is motivated by the recognition that in spite of its many attractive features, a tokamak tends to be a low power density device, ultimately translating into large and corresponding expensive reactor. ITER, as it is currently envisaged, is a good example of a large, expensive, plain vanilla tokamak. In its defense, ITER rightly claims that its base design is very conservative in order to minimize the risk of failure. In order to increase power density and reduce cost there are two qualitatively different approaches that one can follow: discover advanced modes of tokamak operation or develop near alternate concepts. To decide which path to follow is a difficult task because of the uncertainties involved in making accurate comparisons between different concepts at different stages of development. One area, however, that most would agree is meaningful is ideal MHD stability. For any given concept to be credible as a reactor, it must at least be stable against macroscopic ideal MHD modes. The TPX design, for instance, goes to considerable trouble to obtain stability against external kinks:more » a close fitting metallic cage, rotation to stabilize the resistive wall version of the external kink, and, if all else fails, feedback. For credibility any other advanced tokamak or alternate concept should be held to the same standards of ideal MHD stability. As a first step in addressing this requirement we have investigated the stability of the RFP since it can be simply and accurately modeled as a straight cylinder. The RFP is well known to have good stability at high P against internal modes but is very unstable to external modes. We have developed a linear stability code which treats the plasma as an ideal compressible fluid, and includes longitudinal flow and a resistive wall. « less
Pesticides and Herbicides

This review summarizes the most current technical literature dealing with pesticides and herbicides in the environment. Citations included in this review focus primarily on monitoring, analytical methods, toxicology, fate and transport, transformation, and treatment strategies as related to pesticides and herbicides in soils, sediments, surface water and groundwater. Some topics covered in this paper may be related to other reviews in this issue including Agricultural Wastes, Treatment Technologies, Storage, Disposal, Remediation and Closure, Mixing and Transport, Groundwater Quality, Non-Point Sources, and Fate of Environmental Pollutants.
Direct measurement of the d13C signature of carbon respired by bacteria in lakes: Linkages to potential carbon sources, ecosystem baseline metabolism, and CO2 fluxes

Using a novel method to measure the isotopic signature (δd13C) of respiratory CO2 produced by bacterioplankton, we determined the proportion of terrigenous vs. algal‐derived organic carbon (OC) respired by bacteria in a series of eight lakes in southern Que'bec (Canada). The lakes are located within the same general basin but span a large range in trophic status, morphometry, and dissolved OC (DOC) concentrations. Isotopic δ13C values of respired CO2 ranged from ‐28.4‰ to ‐32.5‰ across a gradient of lakes and streams. These values were compared with those of potential OC sources within the lakes (terrigenous and algal) using a mass balance model. The proportion of terrigenous OC respired varied from 3% to >70% and was strongly negatively correlated to lake chlorophyll a (Chl a) concentrations and weakly positively correlated to DOC: Chl a concentrations. While both total plankton and bacterial respiration (BR) increase with lake Chl a concentration, the component of BR that is supported by terrigenous OC, which ranges from 0.7 to 1.7 mg C L‐1 h‐1, stays essentially constant along the trophic gradient, increasing only slightly with DOC concentration. There is a relatively constant baseline BR supported by terrigenous OC, which becomes diluted by the BR of algal OC as the lakes become more productive. The estimated production of CO2 through BR of terrigenous OC in the epilimnion explains on average 60% of the estimated air‐water CO2 flux calculated for these lakes, suggesting that the processing of allochthonous OC by bacteria is a major component of this flux.
New competitive system for tomato's ripeness control

The tomatoes production shows a fast growing in the word. The need of fast industrial process to covert the high request of the second more consumed vegetarian produced after the potatoes, have attracted a considerable interest from both academia and industry. In this article, we develop a model based on high frequency structural simulator (HFSS) to evaluate different armatures of tomatoes for real time monitoring process. Unlike previous techniques, based on image processing, the proposed study presents a new approach of tomatoes evaluation. The tomatoes color may differ from side to another, which limits such solution. The proposed system uses the microwave penetration capability in order to perform 3D tomatoes evaluation. The sensitive of dielectric variation in terms of liquids composite of tomatoes, presents a new criteria for ripeness classification. The proposed model is simulated and experimentally approved for different kinds of tomatoes samples. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2901–2905, 2016
Investigation of the temperature gradient instability as the source of midlatitude quiet time decameter‐scale ionospheric irregularities: 2. Linear analysis

Previous joint measurements by the Millstone Hill incoherent scatter radar and the Super Dual Auroral Radar Network (SuperDARN) HF radar located at Wallops Island, Virginia, have identified the presence of opposed meridional electron density and temperature gradients in the region of decameter‐scale electron density irregularities that have been proposed to be responsible for low‐velocity Sub‐Auroral Ionospheric Scatter observed by SuperDARN radars. The temperature gradient instability (TGI) and the gradient drift instability (GDI) have been extended into the kinetic regime appropriate for SuperDARN radar frequencies and investigated as the causes of these irregularities. A time series for the growth rate of both TGI and GDI has been developed for midlatitude ionospheric irregularities observed by SuperDARN Greenwald et al. (2006). The time series is computed for both perpendicular and meridional density and temperature gradients. This growth rate comparison shows that the TGI is the most likely generation mechanism for the irregularities observed during the experiment and the GDI is expected to play a relatively minor role in irregularity generation.
Determining the rider induced roll torque on dynamic motorcycle riding simulator

While undoubtedly the rider leaning input – in most cases – will not be used solely for following a given trajectory, it has a vast influence on steering forces and handling of powered two wheelers (PTW) due to the bidirectional steer-roll-coupling. Thus, to increase the immersion and rideability on a motorcycle riding simulator, the rider’s body movement is an essential input to the vehicle dynamics calculation.
Asymptotical Tests on the Equivalence, Substantial Difference and Non‐inferiority Problems with Two Proportions

Let d = p2 − p1 be the difference between two binomial proportions obtained from two independent trials. For parameter d, three pairs of hypothesis may be of interest: H1: d ≤ δ vs. K1: d > δ; H2: d ∉ (δ1, δ2) vs. K2: d ∈ (δ1, δ2); and H3: d ∈ [δ1, δ2] vs. K3: d ∉ [δ1, δ2], where Hi is the null hypothesis and Ki is the alternative hypothesis. These tests are useful in clinical trials, pharmacological and vaccine studies and in statistics generally. The three problems may be investigated by exact unconditional tests when the sample sizes are moderate. Otherwise, one should use approximate (or asymptotical) tests generally based on a Z‐statistics like those suggested in the paper. The article defines a new procedure for testing H2 or H3, demonstrates that this is more powerful than tests based on confidence intervals (the classic TOST – two one sided tests – test), defines two corrections for continuity which reduce the liberality of the three tests, and selects the one that behaves better. The programs for executing the unconditional exact and asymptotic tests described in the paper can be loaded at http://www.ugr. es/~bioest/software.htm. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐Resolution Isotopic Variability Across EPR Segment 16°N: A Chronological Interpretation of Source Composition and Ridge‐Seamount Interaction

A high‐resolution sampling profile constituted of 52 basalt samples from across the East Pacific Rise (EPR) was investigated. These samples provide a unique opportunity to study the coeval recording of isotopic signals derived from sub‐marine eruptions at a fast spreading ridge over a time interval of ∼320 kyrs. Additionally, the study area is marked by the presence of a neighboring seamount chain that has recently caused the ridge to jump twice toward it. Combining previous geochemical studies and bathymetry, we established a first‐order chronology between analyzed samples, and have reconstructed the evolution of basalt compositions as the ridge and seamounts advance and finally merge. Our data reveal the existence of two distinct types of isotopic variability within the samples. One that has a low amplitude and frequency and is accounted for by the continuous melting of the ambient mantle, indicating a process with a ∼125 kyr periodicity. The other, of higher amplitude, is discontinuous in time, and likely reflects the seamounts source influence on the ridge. Our results support a two‐step hotspot‐ridge interaction including a first stage (≥600 ka) of regional enrichment of the depleted ridge mantle by hotspot material; and a second, more recent (at least 300 ka) even wherein ambient mantle melts mixed with proximal melts from heterogeneous seamounts sourced nearby. We also propose that the ancient gabbroic component previously identified in this region appeared very recently (
Dropout prediction in MOOCs Using sentiment analysis of users’ comments to predict engagement

dropout, which were discovered in other studies, was not proved by the present data sets. These trends are true for the whole population as well as for separate groups of students – those who completed more than 70 per cent of topics, those who completed less than 30 per cent and the middle group. At the student level the following variables were used for the analysis: an average score, a minimal score, a maximal score, a share of negative comments and a share of positive comments. No significant link was identified neither between average score and completion rate, nor between minimal score and completion rate. These results were received for both courses and for both tracks within xAPI course. To identify the most influential variables more complex models were used such as conditional inference trees which split the population according the value of a parameter with the most statistical significance. Some correlation between the variables and the completion rate was found for different groups. For all courses and tracks one of the lowest completion rate was registered for the group of participants with the highest minimal score. In other words, those who do not express any negative emotions are likely to drop the course very soon. On the other hand, those who express negative emotions a lot are also in the group of risk in terms of completion. The highest completion rate is associated with the group of learners who have some negative comments but not too many. It means that some critical cognitive involvement in the course is vital for succeeding. These findings may influence the focus of MOOC teachers and course developers. Critical comments can be more appreciated as they signal more involvement and, thus, potentially more completion.
Researching and learning together : inter-institutional collaboration as a strategy for capacity building. Keynote symposium paper.

Introduction There is growing awareness of trends in educational research capacity that give cause for concern: the increasingly elderly demographic of education researchers (Mills et al., 2006), the increasing concentration of education funding and research in a small number of research intensive institutions (Pollard,2008), and the possibility that education training might become divorced from its research base. All of these concerns are rapidly becoming manifest in Wales, and it was for this reason that the Welsh Education Research Network (WERN) was formed in order to increase educational research capacity across the principality. The focus of this paper is the social practices model that has been adopted by WERN as the method to develop capacity, how this has been developed through inter-institutional collaboration, and the impact it has had at the individual and institutional levels. The evaluation data that we discuss has been gathered as a part of the of internal evaluation process (a fuller account of this can be found in Davies &Salisbury (in preparation)), or is the result of the external evaluation conducted by Prof. John Gardner, Queen’s University, Belfast (Gardner,2008). The paper will conclude with a summary that reflects on what we have found out about building capacity-in particular what has worked and what has created obstacles – and what we can draw from this for future capacity building initiatives
Estimation of the Short-Term Probability of Failure in Water Mains

AbstractIn this paper, the nonhomogeneous Poisson process (NHPP), hierarchical beta process (HBP), and a new-developed Bayesian simple model (BSM) are used for short-term failure prediction with several water utility failure data sets. The prediction curve was used to investigate the relative ranking of the pipes from the three models. The curve was demonstrated to be more suitable for practical situations compared to the traditional receiver operating characteristic (ROC) curve. The expected number of failures and the effect of incorporating covariates by dividing the pipe assets into smaller pressure cohorts were also examined. Based on the data sets used, the observations from the prediction curves show that the performance of the three models are very similar in terms of pipe ranking. However, the BSM is more advantageous because of its relative simplicity. The covariate, the number of known past failures, plays a very important role when considering the relative ranking of the pipes in the network. T.
In‐Situ Photometric Properties of Lunar Regolith Revealed by Lunar Mineralogical Spectrometer on Board Chang’E‐5 Lander

The photometric properties of the uppermost lunar regolith are used in the spectroscopic study. China's Chang’E‐5 (CE‐5) mission successfully landed in the Northern Oceanus Procellarum of the Moon, carrying the scientific payload lunar mineralogical spectrometer (LMS). LMS performed full‐view scanning and obtained the reflectance spectra in various geometric configurations. The photometric properties, including the single‐scattering albedo ω and two parameters of the Henyey‐Greenstein phase function (b, c), were derived. Our modeling results showed weak backward scattering and strong forward scattering properties of the regolith at the CE‐5 landing site. Meanwhile, the asymmetry parameter (−b×c) $(-b\times c)$ indicates that CE‐5 regolith has weaker forward scattering than the Apollo lunar soil samples and the regolith at the Chang’E‐4 landing site. The derived Hapke parameters can be used for comparison with that of the returned lunar sample, supporting further studies of lunar spectroscopy, and can be the ground truth of the CE‐5 landing area.
The authors replied as follows:

Lin and coauthors have presented a method for conducting sensitivity analysis for unmeasured confounding in observational studies (Lin, Psaty, and Kronmal, 1998). They described simple algebraic relationships between the true exposure effect and the apparent exposure effect in a variety of regression models. The simplicity of the method relies on the assumption of conditional independence of the measured confounders Z and a generic unmeasured confounder U given the exposure X . The authors argue that this assumption would be satisfied, e.g. ,whenever Z consists of environmental factors and U is a genetic trait. To us, this example would suggest that Z and U are marginally independent but not that they are conditionally independent given X because, if Z and U are confounders, each must be marginally correlated with the exposure X . But it is easy to show that the following holds for three dichotomous variables X , Z, and U .