Miracle-dz/UniFAR-FTUs huggingface dataset:
Sensitivity analysis of entropy-constrained designs of water distribution systems

A study of the relationship between the statistical entropy and hydraulic reliability of water distribution systems (WDS) was carried out by assessing the effects of layout, flow direction, and pipe costs. Because of an invariance property of the entropy function, different WDS layouts can have identical maximum entropy values. The properties of designs that have identical maximum entropy values were also compared. The results reinforce previous observations that entropy is a potential surrogate measure for hydraulic reliability and suggest that any influences due to the design factors mentioned above are negligible. Maximum entropy designs are shown to be more reliable than other designs, while designs with different layouts but equal maximum entropy values have very similar levels of reliability. The head-dependent analysis method was used and revealed the correlation between entropy and reliability more clearly than hitherto achieved using demand-driven analysis.
Detection of Normal and Paradoxical Splitting in Second Heart Sound (S2) using a Wearable Accelerometer Contact Microphone

Second heart sound (S2) splitting can potentially be used as an indicator for diagnosis of cardiovascular diseases. One example is S2 paradoxical splitting, which can occur when the pulmonic sound (P2) occurs before the aortic sound (A2). However, current means of capturing S2 sounds are not sensitive enough for quantification of A2 and P2. In this paper, we present that S2 's acoustic signatures can be captured accurately using a wearable hermetically sealed sensitive accelerometer contact microphone (ACM) MEMS device. Smoothed Pseudo Wigner-Ville distribution is used to extract the S2 splitting interval. This methodology has been used to capture S2 splitting from patients with varying BMI and used to identify paradoxical splitting from patients with known heart diseases such as aortic stenosis.
Design of Vehicle Speed Tracking Controller Based on The UniTire Model

In this paper, the characteristics of different roads and speeds can be expressed uniformly by using the Unitire model, and a speed tracking controller which can adapt to many kinds of roads and different speeds is established. The longitudinal force of the vehicle at the current moment is obtained from the tire model, the vehicle speed is serve as the input of the MPC controller; the optimization function takes the reference speed as the target, constrains the acceleration and the change of acceleration, and obtains the expected acceleration; the expected acceleration is taken as the input of the lower controller, and through the automobile inverse dynamic model, it is transformed into the control of engine throttle opening and brake master cylinder pressure. The simulation effects exhibit that the controller has well applicability on diverse roads and speeds, and maintains the speed tracking accuracy without losing the stability of the vehicle.
Comparison of Modulation Strategies for a Dual Active Bridge Partial Power DC-DC Converter in EV Powertrains

Electromobility has been growing rapidly in recent years, as a result of green and sustainability policies that promote it, but its growth has been hampered by having less autonomy than combustion vehicles, not being able to directly replace them especially in heavy-duty electric vehicles powertrains. The main objective of this work is to propose an improvement to an already implemented Bidirectional Dual-Active-Bridge (DAB) Partial Power Converter (PPC) topology, seeking to boost efficiency by testing different modulations. The modulation study applied to PPC is interesting in order to identify the cases where the RMS current in the transformer is minimized. Results of the study shows that efficiency of the DAB-based PPC can be optimized by using the correct modulation, with a possible maximum efficiency of 99.41% at 6.526 kW.
An Fault-tolerant Control Approach for Event-triggered Consensus of Multiple Robotic Manipulators with Switching Topologies

A new fault-tolerant controller is designed in this paper, which ensures the event-triggered leader-following consensus of multiple robotic manipulators subject to switching topologies. A Markov distributed sequence with a known probability transition matrix is employed to describe the switching communication topologies of multiple robotic manipulators. The investigated actuator fault model contains both constant and time-varying faults. Also, the norm-bounded conditions are utilized to denote the manipulators nonlinearities and additive noises. Furthermore, a set of output-based control gains are explicitly characterized via ensuring mean-square stability on dynamics of consensus errors. Finally, simulation results illustrate the designed consensus protocol can compensate actuator failure effectively.
Detection of Left Ventricular Ejection Fraction Abnormality Using Fusion of Acoustic and Biopotential Characteristics of Precordium

This study develops a wearable monitoring platform for the detection of abnormal left ventricular ejection fraction (LVEF) using a fusion of an accelerometer contact microphone (ACM) and an electrocardiogram (ECG) sensor. Two signal processing chains are designed to annotate ACM and ECG recordings. Afterwards, the pre-ejection period (PEP) and left ventricular ejection time (LVET) are estimated as the time difference between the first heart sound (S1) and the R-peak in ECG signals, and the time difference between the first and second heart sounds (S1 and S2), respectively. The ratio of PEP to LVET is then utilized to differentiate between healthy and abnormal-LVEF groups. The model is evaluated on 15 subjects (8 healthy subjects and 7 subjects with LVEF abnormality) where the ground truth values are the LVEF parameter acquired by the echocardiography machine. An average (± standard deviation) accuracy of 84.47% (± 17.58%) is obtained for the detection of LVEF abnormality for a total of 5989 heartbeats. It is demonstrated that the proposed method is capable of LVEF abnormality detection with accuracies within the range of 54.35% - 100%.
Parabolic equations for curves on surfaces Part I. Curves with $p$-integrable curvature

This is the first of a two-part paper in which we develop a theory of parabolic equations for curves on surfaces which can be applied to the so-called curve shortening of flow-by-mean-curvature problem, as well as to a number of models for phase transitions in two dimensions. We introduce a class of equations for which the initial value problem is solvable for initial data with p-integrable curvature, and we also give estimates for the rate at which the p-norms of the curvature must blow up, if the curve becomes singular in finite time. A detailed discussion of the way in which solutions can become singular and a method for "continuing the solution through a singularity" will be the subject of the second part.
On Near-Optimal Codebook and Receiver Designs for MIMO-SCMA Schemes

Sparse code multiple access (SCMA) is a promising code-domain non-orthogonal multiple access (NOMA) technique that supports high-level connectivity. Through the combination of SCMA and multiple-input multiple-output (MIMO) techniques, MIMO-SCMA schemes are capable of enhancing the overall spectral efficiency. This paper proposes novel MIMO-SCMA designs for both uplink and downlink Rayleigh fading channels. Rather than directly combining the SCMA and spatial multiplexing techniques presented in the previous literature, the proposed designs consider not only the frequency or time diversity, but also simultaneously include space diversity. Codebook design criteria for different transmission scenarios are respectively investigated, and a low-complexity codebook design algorithm is proposed based on the cross-entropy method. In addition, since the new designs suggest a dense factor graph, conventional message-passing algorithm (MPA)-based detectors are less suitable. Consequently, low-complexity MIMO-SCMA codeword detectors based on depth-first and breadth-first tree-search algorithms are respectively investigated. It is shown that the overall designs are able to simultaneously achieve a higher diversity order, enhanced BER results, and lower levels of detection complexity for both uplink and downlink scenarios, when compared to conventional MIMO-SCMA schemes.
Exploring a Modular Architecture for Sensor Validation in Digital Twins

Decision-support systems rely on data exchange between digital twins (DTs) and physical twins (PTs). Faulty sensors (e.g, due to hardware/software failures) deliver unreliable data and potentially generate critical damages. Prompt sensor fault detection, isolation and accommodation (SFDIA) plays a crucial role in DT design. In this respect, data-driven approaches to SFDIA have recently shown to be effective. This work focuses on a modular SFDIA (M-SFDIA) architecture and explores the impact of using different types of neural-network (NN) building blocks. Numerical results of different choices are shown with reference to a wireless sensor network publicly-available dataset demonstrating the validity of such architecture.
Enhancing Object Localization Accuracy by using Multiple Camera Viewpoints for Disassembly Systems

The number of images taken from different view-points plays an important role in the accuracy of object detection in cluttered scenarios. Considering Electric Vehicles battery pack disassembly task, which is a highly dense clutter, a framework is proposed to approximate the number of viewpoints to acquire the accuracy of 3.82 mm in screw detection. The paper explores two methods of image acquisition i) taking multiple 3D images, and ii) taking one 3D image and multiple 2D images and combines it with two methods of image processing i) marking the exact visible center of the screw for calculation, and ii) using a bounding box to mark the screw and calculating the center by intersecting diagonals. The results show that using eight viewpoints with a reliable 3D camera delivers the optimal results.
Diabatic Divergence Profiles in Western Pacific Mesoscale Convective Systems

Abstract Heating in the atmosphere can be expressed as diabatic divergence δd, which is nearly equal to the actual horizontal divergence δ in tropical convection. High-quality δ profile measurements from airborne Doppler radar “purls” in ten mesoscale convective systems (MCS) observed during TOGA-COARE are examined, and the mean profile is compared with rawinsonde array measurements. Young convective features have strong near-surface convergence, while older cells with better-developed downdrafts and stratiform precipitation areas have their peak convergence aloft. In the mean, then, surface flow is only weakly convergent or oven divergent, so that the main convergence into MCSs is deep and peaked aloft, with a sharp “melting convergence” at 0°C. Divergence prevails above ∼10 km altitude but was undersampled by the radar. Unusual but well-sampled observations in the purl dataset include: a persistent, widespread δ profile feature in one well-sampled MCS (a cyclone rainband); oscillatory “reverberations” c.
A Kernel-Type Estimator of a Quantile Function from Right-Censored Data

Abstract Based on right-censored data from a lifetime distribution F 0, a kernel-type estimator of the quantile function Qo (p) = inf{t: F 0(t) ≧ p}, 0 ≦ p ≦ 1, is proposed. The estimator is defined by , which is smoother than the usual product-limit quantile function , where denotes the product-limit estimator of F 0 from the censored sample. Under the random censorship model and general conditions on hn, K, and F 0, it is shown that Qn (p) is strongly consistent. In addition, an approximation to Qn is shown to be asymptotically equivalent to Qn with probability one. A small Monte Carlo simulation study shows that for several values of the bandwidth hn, Qn performs better than in the sense of estimated mean squared errors. An optimal bandwidth hn may be estimated by bootstrap methods in some cases. The procedure is illustrated by an application to data from a mechanical-switch life test.
SHIMURA INTEGRALS OF CUSP FORMS

This paper studies integrals of the form on the upper half-plane, where is a rational number, is integral, and is a cusp form of weight with respect to some modular group . The main result is that if is a congruence subgroup and is an eigenvector of all the Hecke operators, then all these integrals are representable as linear combinations of two complex numbers with coefficients in some field of algebraic numbers. Bibliography: 13 titles. Figures: 11.
Desensitized Strategies for Pursuit-Evasion Games with Asymmetric Information

In this paper, we analyze two-player zero-sum dif-ferential games with asymmetric information. In the proposed formulation, asymmetric information is associated with the knowledge about a vector of model parameters that is subject to variations about a nominal value. It is assumed that one of the players knows only the nominal value of the parameter vector while the other player has also information about the parameter variations. Conservative strategies are developed using sensitivity functions for the minimizing player, which is the player at an information disadvantage. The proposed approach is tested for pursuit-evasion games with an uncertain dynamic obstacle, where the pursuer is assumed to know only the nominal value of the obstacle's speed.
Influence of Ball Grid Array Design Parameters on Solder Joint Reliability

Ball grid array (BGA) package is widely used in electronic packaging. This type of package can accommodate high I/O in the small form factor package size compared to the quad-flat package (QFP) and quad-flat no-lead (QFN). Due to its function to electrically connect the package substrate to the printed circuit board (PCB), it is important to ensure the 2nd level interconnect is reliable against cyclic thermo-mechanical load. Ever-increasing functional density in microelectronic components requires a continuous redesign of packaging technology. Characteristic attributes are form factor, pin count, pitch, power density, diverse application and harsh environment. Packaging engineers have to ensure new product designs will act according to specifications and will survive in the field for the targeted market. The interconnection of the semiconductor package and PCB is one of the most critical elements in the electronic control unit. A thermal mismatch between component and PCB, together with varying temperatures causes cyclic deformation and fatigue of solder interconnect. The semiconductor manufacturers apply an accelerated temperature cycling test to assess the risk for early failure in the field. To reduce the development cycle, NXP is applying virtual prototyping and testing by simulation. This allows to run extensive design studies in a relatively short time with only a few prototype builds for empirical validation. NXP has established robust simulation technics for the assessment of fatigue in solder alloys. In this paper, we want to share a design study for BGA. We will derive the significance of various design parameters concerning the solder joint reliability in a board assembly. For instance, we will assess the influence of PCB pad diameter, solder stand-off height, solder alloy materials, die sizes and package core thickness. The simulations described in this paper are done during the early design stage to ensure all NXP products are robust and reliable. To evaluate the relative failure risk between design cases, a volume average approach on the accumulated creep energy density is used. We will discuss the significance of mentioned design parameters with respect to the board-level reliability test conditions. We will provide, a few guidelines from a mechanical standpoint to mitigate solder joint bulk fatigue under board level temperature cycling (BLTC) test conditions.
Utilizing Lateral Plate Transducer Modes for High Quality Acoustofluidics in Silicon-Based Chips

By establishing and exploring a numeric model of an acoustofluidic device driven by a piezoelectric plate transducer, we discovered simple and distinct vibrational patterns with high displacement amplitudes for a lateral vibrational mode of the transducer plate. With the design based on a numerically optimized chip-geometry for this particular lateral mode, we fabricated high-performant chips enabling rapid and accurate particle focusing, where the acoustic energy density is exceeding 100 J/m3 at actuation frequencies around 540 kHz, while heat generation remains low. We excite higher order harmonics leading to multiple separate lines of particles along the channel. With the custom-made chip holder featuring integrated fluid connections and transducer support, we are moreover able to swiftly mount microfluidic chips directly after dicing without any further preparation.
Inverse Problems in Astronomy, A guide to inversion strategies for remotely sensed data

In many research fields the basic properties of a system have to be deduced from remotely sensed observations rather than from first-hand on the spot measurements. These remotely sensed data are often difficult to interpret physically because they emerge as severely filtered convolutions of the original source function. The central 'inverse' problem is to transform these data, through integral inversion techniques, into stable and physically meaningful representations of the source. This book gives a general mathematical introduction to the subject and illustrates it with examples and applications in astronomy. The authors outline the classical theory of itegral inversion and illustrate why classical techniques fail, then go on to describe and compare a variety of non-classical techniques. Methods such as regularisation, employing smoothing constraints and the use of a priori information such as non-negativity are carefully explained and applied to contemporary research problems in astronomy. Finally, the way to develop an optimal overall strategy is discussed. This is the first book to address all aspects of inverse problems, from how they occur to their analytic formulation and practical numerical treatments. Enough mathematical detail is incorporated for the text to be self contained. As such it will primarily be of interest to postgraduate and research astronomers and physicists, and to applied mathematicians. Other workers in passive observational studies such as meteorology, and areas of economics and sociology will find chapters on theory and strategy useful. Attention is also drawn to implications of inverse theory for a central tenet in the philosophy of science, namely falsifiability of hypotheses.
Robust Parameter Estimation and Tracking through Lyapunov-based Actor-Critic Reinforcement Learning

This work presents an approach for parameter estimation of nonlinear systems by means of robust maximum entropy offline reinforcement learning (RL). The identification of parameter variant systems is a challenging problem in industrial applications. We address the parameter estimation on disturbed measurements with an actor-critic RL agent that is extended by a Lyapunov neural network. Accordingly, a robust soft actor-critic algorithm (RSAC) is applied to the parametrization problem. The policy is learned on test trajectories and can be applied to identify nonlinear system parameter maps for comparable system dynamics across an operating range. In a simulative study, the performance of the proposed concept is shown for a permanent magnet synchronous machine model in the d/q-frame formulation with current dependent and nonlinear flux linkages. The trained RL agent is evaluated on a different nonlinear machine parameter set under noisy measurements. The results indicate applicability to real-world tasks such as system parameter tracking.
A robust 2D shallow water model for solving flow over complex topography using homogenous flux method

A robust Godunov‐type numerical scheme solver is proposed for solving 2D SWEs and is applied to simulate flow over complex topography with wetting and drying. In reality, the topography is usually complex and irregular; therefore, to avoid the numerical errors generated by such features, a Homogenous Flux Method is used to handle the bed slope term in the SWEs. The method treats the bed slope term as a flux to be incorporated into the flux gradient and so maintains the balance between the two in a Godunov‐type shock‐capturing scheme. The main advantages of the method are: first, it is simple and easy to implement; second, numerical experiments demonstrate that it can handle discontinuous or vertical bed topography without any special treatment and third, it is applicable to both steady and unsteady flows. It is demonstrated how the approach set out here can be applied to the nonlinear hyperbolic system of the SWEs. The two‐dimensional hyperbolic system is then solved by use of a second‐order total‐variation‐diminishing version of the weighted average flux method in conjunction with a Harten‐Lax‐van Leer‐Contract approximate Riemann solver incorporating the new flux gradient term. Several benchmark tests are presented to validate the model and the approach is verified against experimental measurements from the European Union Concerted Action on Dam Break Modelling project. These show very good agreement. Finally, the method is applied to a volcano‐induced outburst flood over an initially dry channel with complex irregular topography to demonstrate the technique's capability in simulating a real flood. Copyright © 2013 John Wiley & Sons, Ltd.
Rankin-Selberg convolutions of generalized theta series.

§ 0. Introduction. In the theory of metaplectic forms, a modern formulation has been recently established in [KP]. It allows one to deal with an analogue of the classical theta series in a more general Situation. According to Kubota in [K], one constructs a generalized theta series Θ (g) s a residue of Eisenstein series JE (g, ω) οη the global metaplectic group GA. This corresponds to an irreducible automorphic representation F0(co) of A, which we call an exceptional representation. Similarly to the JacquetLanglands theory, V0(co) is isomorphic to a kind of tensor product of the so-called local exceptional representations V0tV(cov) of local metaplectic groups v over the places v of the ground field k.
A Review of UPFC Applications in Improving Power System Stability

: The stability of power systems has been one of the major concerns of modern electrical power systems. The UPFC, a versatile FACTS controller, allows simultaneous or independent control of parameters like line impedance, voltage or power angle so that it can be used for voltage support, transient/dynamic stability improvement and damping of low frequency power system oscillations. This paper presents a review of various applications which UPFC provides in a power system such as minimization of loss, enhancement of loadability, voltage stability ,transient stability, damping of power oscillations etc. by setting up UPFC parameters. To seek better power flow control, optimal allocation and parameter settings of UPFC in power system can be done by various evolutionary techniques.