Miracle-dz/UniFAR-FTUs huggingface dataset:
Robust Fault Detection for Uncertain Discrete-Time Systems

The fault detection problem under structured uncertainties in the system matrices is considered. The sensitivity of robust fault detection is one of the important issues considered in the fault detection and isolation development. To enhance this characteristic, an unconstrained optimization approach is taken to design a robust fault detection observer. The approach aims at enhancing the fault detection robustness to uncertainties without sacrie cing the faultdetectionsensitivity,whichwasseldomaddressedbefore.Furthermore,otherobjectivesrelatedtotheobserver gain and the eigenstructure conditioning of the observer system are also taken into account. The gradient-based optimization approach is facilitated by the explicit gradient expressions derived. Numerical simulation has also demonstrated the tradeoffs between different objectives as well as the effectiveness of the present methodology. I. Introduction T HE research and application of fault detection and isolation in automated processes has received considerable attention during thelast twodecades, 1i6 both ina research contextandalsointhe domain of application studies on real processes. One area of active research isthe developmentofmodel-basedfaultdetection systems. There are a great variety of methods in the literature to construct model-based fault detection systems. One of them, using observer techniques, has received much attention in the past. Modern technology has increasingly led to the creation of highly complex dynamic systems that have demanding performance requirements in a variety of environments. These systems must be capable of meeting stringent specie cations for reliability and operational safety over long periods of time, while operating under a great deal of uncertainty. However, in practice, such as in chemical processes or aerospace systems, fully accurate mathematical models of the systems cannot be obtained. There is always a mismatch between the actual process and its mathematical model even if there is no fault in the process. Such inaccuracies may give rise to false alarms and, thus, corrupt the performance of the fault detection system, which may even render it useless. To overcome this dife culty, the fault detection system has to be made robust, that is, insensitive or even invariant to such modeling errors. More specifically, a mere reduction of the sensitivity to modeling errors does
Die Stabilität der Strömung in einem gekrümmten Kanal

ZusammenfassungDie Wirbelinstabilität einer laminaren Strömung durch einen gekrümmten, unendlich hohen Kanal, dessen Breite klein ist gegenüber den Krümmungsradien der Kanalwände, wird durch die beiden Differentialgleichungen (2) beschrieben. Das System (2) stellt ein Eigenwertproblem dar, bei dem vor allem die kleinsten Eigenwerte S1 in Abhängigkeit von dem Parameter σ mit den zugehörigen Eigenfunktionen interessieren; dabei beziehen wir uns bereits auf (3), wo neutrale Störungen (τ=σ) betrachtet werden, und S1(σ) ist bis auf einen Zahlenfaktor die kritische Kurve des Parameters 2 Re2d/R1 in Abhängigkeit von der Dicke λ/2 der angesetzten Wirbel. Mit Hilfe Greenscher Funktionen werden die Differentialgleichungen (3) in die Integralgleichungen (4) verwandelt, die es zunächst erlauben, untere Schranken für S1(σ) anzugeben (Fig. 2). Das Iterationsverfahren nach [9] liefert S1(σ) mit hinreichender Genauigkeit nach wenigen Iterationsschritten (Fig. 3). Ebenso ergeben sich damit die Eigenfunktionen (Fig. 4), also die Wirbelkomponenten, so daß in Fig. 5 das Aussehen der neutralen Wirbel angegeben werden kann. Der kritische Wert — aus dem kleinsten unter den Eigenwerten. S1(σ) — ist 2Re2d/R1=5740, während Dean [2] 1928 den ebenfalls richtigen Wert 5832±2,5% gefunden hatte. Die zugehörige kritische Wirbeldicke ist λ/2=0,79 d. Die Ergebnisse von Yih und Sangster [3] erweisen sich als falsch. Die Arbeit verfolgte zwei Ziele: Eine Neubehandlung der Differentialgleichungen (5) mit exakt begründeten Methoden, um eine Beurteilung der Ergebnisse von Dean und von Yih und Sangster möglich zu machen. Dann die Angabe der Eigenfunktionen, die es gestatten, das Aussehen der entstehenden Wirbel zu beschreiben.
Role of Intravenous Iron Sucrose in Severe Anemia in Late Pregnancy: A Case Report From Rural Ballabgarh, Haryana

Severe anemia is a high-risk factor in pregnancy and needs to be treated appropriately to prevent poor maternal and fetal outcomes. A pregnant woman with severe anemia reluctant for blood transfusion due to issues of accessibility was given four doses of 300 mg intravenous iron sucrose (IVIS) in 300 ml normal saline starting at 31 weeks 5 days of gestation and her hemoglobin level increased by 4.2 gm/dl over a period of five weeks without any complications and without any intake of iron and folic acid tablets during the entire duration. Intravenous iron sucrose is a useful intervention for severe anemia of pregnancy even in late pregnancy with rapid increase in haemoglobin levels and can be used regularly for treating severe anemia in pregnant women alternative to blood transfusion who have limited accessibility to blood transfusion facilities.
A numerical investigation of Preisach and Jiles models for magnetic hysteresis

The Preisach and Jiles models for hysteresis are applied to reconstruct BH loops from measurement data for constructional steel St 37. The distribution function for the Preisach model is determined from all the available, 18, measured BH loops starting from the initial curve. The five unknown parameters in Jiles model are determined by the simulated annealing method to minimize the distance between the largest measured BH loop and the corresponding computed loop. Although Jiles model gives differences from the measured BH loops for low applied fields, it provides results fitted well to the largest measured loop for which the parameters are optimized. The Preisach model gives good fitting over a wide range of the applied field.
Terahertz gain on shallow donor transitions in silicon

Small signal gain measurements of optically excited terahertz silicon lasers are reported. Two types of lasers, Si:P and Si:Bi, were investigated. They were optically excited with radiation from a free electron laser or a CO2 laser. The experiments were performed with an oscillator-amplifier scheme where one sample serves as a laser while the other one is an amplifier. In case of the free electron laser the pump frequency corresponds to intracenter excitation of the 2p0 or 2p± states of the P and Bi Coulomb centers, and the gain was determined for the 2p0? 1s(E), 2p0? 1s(T2) transitions in Si:P and the 2p±? 1s(E) transition in Si:Bi. Pumping with a CO2 laser leads to photoexcitation of the Coulomb centers. In this case the gain was determined for the 2p0? 1s(T2) of Si:P transition. The gain for intracenter pumping is in the range 5? 10? cm? 1 while for photoexcitation the gain is considerably less, namely ? 0.5? cm? 1. The experimental results are analyzed and found to be in good agreement with theoretical calculations based on balance equations.
Destruction of ozone at the earth's surface

Several hundred new measurements of the surface resistance to ozone uptake of grass, soil, sand, fresh water, sea water and snow are presented. Grass and soil show, in agreement with previous work, a daytime surface resistance of median value 100 sm−1. The first direct evidence is presented of a nocturnal increase in surface resistance for grass and soil, with night-time values of surface resistance of about 300 sm−1. The surface resistances of sea water and snow are considerably larger, about 1000 to 2000 sm−1. A representative global ozone destruction rate for the earth's surface is derived using the above information and other published ozone data. Allowance is made for the latitudinal variation of the different types of surface, their various ozone destruction constants, the latitudinal and diurnal variation of ozone in the surface air and the diurnal variation of eddy transfer near the earth's surface. The global average ozone destruction rate is estimated to be in the range 2 to 6 × 1029 molecules s−1 (0.5 to 1.5 × 1012kg yr−1). This range extends to slightly higher values than previous estimates. The ratio of ozone destruction rate between the southern and northern hemispheres is about 2:3. The implications for the tropospheric ozone cycle are discussed.
Sliding mode control of two-dimensional systems in Roesser model

The study is concerned with the problem of sliding mode control of two-dimensional (2D) discrete systems. Given a 2D system in Roesser model, attention is focused on the design of sliding mode controllers, which guarantee the resultant closed-loop systems to be asymptotically stable. This problem is solved by using two different methods: model transformation method and Choi's 1997 method. In terms of linear matrix inequality, sufficient conditions are formulated for the existence of linear switching surfaces guaranteeing asymptotic stability of the reduced-order equivalent sliding mode dynamics. Based on this, the problem of controller synthesis is investigated, with two different controller design procedures proposed, which can be easily implemented by using standard numerical software. A numerical example is provided to illustrate the effectiveness of the proposed controller design methods.
New Spectral Observations of the Variable Galaxy Kaz 163

Abstract Kaz 163 is a close double galaxy. Its southern component S is compact, with a very blue nucleus, in which heated active processes take place. From time to time gas formations are ejected from it, which behave themselves like emission components around the main emission lines Hα and Hβ, around both from their long-wave and short-wave sides. This paper presents the spectral data of new observations, which were carried out with the 2.6m telescope at the Byurakan Astrophysical Observatory in September 2011. During the former observation in October 1981, lines [NII] λλ 6584,6548 were not visible in the spectrum of the component S. In 2001 they were already visible on the spectrum, and on the spectrum obtained in 2011 they already surpassed the intensity of Hα. The magnitude of the component S is also changing: its nucleus is very blue and its U-B = −0m.63. In the soft X-ray spectral range (0.1–2 keV) the flux of the radiation changed by 45% during 55,000 sec, and in the hard one (2–10keV) it changed up to 3.4 times. Photoindices Γ for the soft and hard ranges in the spectrum of galaxy S, unlike other objects, do not so much differ from each other. The mean value for the first interval is approximately 2.5 and is equal −2.0 for the second one. On the histogram of redshifts Kaz 163 corresponds to the first big peak of the distribution. It is concluded that the component S of the galaxy Kaz 163 is a NLS1 galaxy, with the development of their evolution, is in the preliminary stage. Component N is a normal elliptical galaxy with no activity.
The hydrodynamic structure of unstable cellular detonations

The study analyses the cellular reaction zone structure of unstable methane–oxygen detonations, which are characterized by large hydrodynamic fluctuations and unreacted pockets with a fine structure. Complementary series of experiments and numerical simulations are presented, which illustrate the important role of hydrodynamic instabilities and diffusive phenomena in dictating the global reaction rate in detonations. The quantitative comparison between experiment and numerics also permits identification of the current limitations of numerical simulations in capturing these effects. Simulations are also performed for parameters corresponding to weakly unstable cellular detonations, which are used for comparison and validation. The numerical and experimental results are used to guide the formulation of a stochastic steady one-dimensional representation for such detonation waves. The numerically obtained flow fields were Favre-averaged in time and space. The resulting one-dimensional profiles for the mean values and fluctuations reveal the two important length scales, the first being associated with the chemical exothermicity and the second (the ‘hydrodynamic thickness’) with the slower dissipation of the hydrodynamic fluctuations, which govern the location of the average sonic surface. This second length scale is found to be much longer than that predicted by one-dimensional reaction zone calculations.
Social capital, joint knowledge creation and relationship performance in buyer-supplier relationships

ABSTRACT Extant studies have shown that despite the seemingly beneficial outcomes of social capital, its impact on buyer-supplier relationships could sometimes be detrimental. This study contributes to a scholarly understanding of the mechanism via which the positive outcome of social capital in realised in buyer-supplier relationships. Drawing on the knowledge-based view of the firm, we theorise and provide empirical support for our thesis that joint knowledge creation acts as a conduit through which social capital enhances relationship performance. We used survey data from 113 construction firms in Ghana to test our propositions using the partial least squares structural equations modelling algorithm. Our findings show that social capital, in all its three dimensions contributes to joint knowledge creation in buyer-supplier relationships. Additionally, the relationship between social capital and relationship performance is mediated by joint knowledge creation. The theoretical and practical implications of these findings are discussed in the paper.
Consensus analysis for a class of mixed-order multi-agent systems with nonlinear consensus protocols

The consensus problem for a class of mixed-order multi-agent systems is investigated in this paper, where the multi-agent system is composed of first- and second-order dynamic agents. Firstly, consensus protocols are proposed for solving the finite-time consensus problem for mixed-order multi-agent systems. By employing the finite-time stability theory and LaSalle’s invariance principle, some sufficient conditions for finite-time consensus are given for multi-agent systems with directed communication topologies. Then, a class of nonlinear consensus protocols are given to solve the asymptotic consensus problem for mixed-order multi-agent systems. In addition, an invariant quantity is introduced to specify the expressions of the final consensus states when asymptotic consensus is reached. Finally, a simulation example is provided to demonstrate the effectiveness of the theoretical results.
Microwave transmission through a two-dimensional, isotropic, left-handed metamaterial

We present experimental data, numerical simulations, and analytical transfer-matrix calculations for a two-dimensionally isotropic, left-handed metamaterial (LHM) at X-band microwave frequencies. A LHM is one that has a frequency band with simultaneously negative eeff(ω) and μeff(ω), thereby having real values of index of refraction and wave vectors, and exhibiting extended wave propagation over that band. Our physical demonstration of a two-dimensional isotropic LHM will now permit experiments to verify some of the explicit predictions of reversed electromagnetic-wave properties including negative index of refraction as analyzed by Veselago [Usp. Fiz. Nauk 92, 517 (1964), Sov. Phys. Usp. 10, 509 (1968)].
Uniaxial-stress dependence of the first-order Raman spectrum of rutile-type crystals. III. Mg F 2

We investigate the uniaxial-stress dependence of ${\ensuremath{\Gamma}}_{1}$, ${\ensuremath{\Gamma}}_{3}$, and ${\ensuremath{\Gamma}}_{5}$ Raman-active modes of Mg${\mathrm{F}}_{2}$ and deduce the deformation potentials associated with uniaxial compressions parallel to the $\stackrel{\ensuremath{\rightarrow}}{\mathrm{c}}$, $\stackrel{\ensuremath{\rightarrow}}{\mathrm{a}}$, or ${\stackrel{\ensuremath{\rightarrow}}{\mathrm{a}}}^{\ensuremath{'}}$ crystallographic axis, respectively. Next, we compute theoretical values considering both the stress-induced change in the short-range lattice potential and the long-range Coulomb interaction. Very satisfactory agreement is found between experimental and theoretical values.
Blood and milk metabolites of Holstein dairy cattle for the development of objective indicators of a subacute ruminal acidosis

Objective The purpose of this study was to perform a comparative analysis of metabolite levels in serum and milk obtained from cows fed on different concentrate to forage feed ratios. Methods Eight lactating Holstein cows were divided into two groups: a high forage ratio diet (HF; 80% Italian ryegrass and 20% concentrate of daily intake of dry matter) group and a high concentrate diet (HC; 20% Italian ryegrass and 80% concentrate) group. Blood was collected from the jugular vein, and milk was sampled using a milking machine. Metabolite levels in serum and milk were estimated using proton nuclear magnetic resonance and subjected to qualitative and quantitative analyses performed using Chenomx 8.4. For statistical analysis, Student’s t-test and multivariate analysis were performed using Metaboanalyst 4.0. Results In the principal component analysis, a clear distinction between the two groups regarding milk metabolites while serum metabolites were shown in similar. In serum, 95 metabolites were identified, and 13 metabolites (include leucine, lactulose, glucose, betaine, etc.) showed significant differences between the two groups. In milk, 122 metabolites were identified, and 20 metabolites (include urea, carnitine, acetate, butyrate, arabinitol, etc.) showed significant differences. Conclusion Our results show that different concentrate to forage feed ratios impact the metabolite levels in the serum and milk of lactating Holstein cows. A higher number of metabolites in milk, including those associated with milk fat synthesis and the presence of Escherichia coli in the rumen, differed between the two groups compared to that in the serum. The results of this study provide a useful insight into the metabolites associated with different concentrate to forge feed ratios in cows and may aid in the search for potential biomarkers for subacute ruminal acidosis.
The Hawking effect for a collapsing star in an initial state of KMS type

We prove the Hawking effect for gravitational collapse of a charged star in an expanding universe or not, stationary in the past and collapsing to a black hole in the future. In the past, the quantum initial state of the Dirac fields was given by a KMS state with unspecified temperature. With the same physical model, this paper generalizes our previous work to the case of a quantum initial state of KMS type rather than a Boulware vacuum.
ON THE SOLUTION OF THE COMPRESSIBLE FLOW EQUATIONS AT SMALL MACH NUMBERS

The present paper focuses on the development of a code capable of performing numerical simulations of transient flows at all speeds. For this purpose, we employ an algorithm based on the dual-time preconditioning of the compressible flow equations developed by the aerospace research community throughout the past two decades. Using this procedure, the fluid mechanics and heat transfer phenomena associated not only with compressible flows but also with incompressible flows as well can be simulated using a single robust algorithm. In order to demonstrate such characteris- tics, classical one-, two- and three-dimensional incompressible problems are solved with this algorithm, namely: Couette and Poiseuille flows (1D), planar mixing-layer (2D), and free jet (3D). These results were obtained with a code prepared under a Finite-Difference framework using a non-uniform Cartesian grid, second-order standard central differencing with a fourth-order preconditioned artificial dissipation, second-order implicit physical-time marching and implicit Euler pseudo-time marching with approximate factorization.
Feige 24 - A very hot white dwarf

OAO-2 ultraviolet photometry of the composite spectrum white dwarf Feige 24 is compared with model atmospheres to derive an effective temperature of 70,000 (+20,000, -15,000) K. The distance to this star is estimated to be 90 (+55, -31) pc if the cool component is assumed to be a main-sequence star with a red and near-infared energy distribution that is normal for its spectral type. The derived characteristics of Feige 24 are compatible with its identification as the extreme-ultraviolet source observed by Margon et al. (AIP)
The Use of an Iterated Moving Average in Measuring Seasonal Variations

Abstract This paper presents a time-saving method for computing an iterated moving average with triangular weights to better represent the trend-cycle elements in a time-series for measuring seasonal variation. A printing-adding machine is used to obtain progressive summation of the Y-data values of a time series. A stencil having three suitably spaced slots is used to disclose progressively the three terms which are summed to obtain the graduated series required. Multiplied by the reciprocal of the weights the graduated series is reduced to the moving average desired. The moving average is extended to both ends of the series by means of a truncated weight function. Computation of the seasonal indexes is otherwise conventional. Tested against a synthetic series with known seasonals and the Census Bureau test series for seasonal computations, the iterated moving-average method is found to be superior to others now in use.
Effect of Micro-slip on the Damping Capacity of Jointed Riveted Structures with Unequal Thickness

This paper addresses the influence of the partial slip phenomenon on the damping capacity of jointed riveted structures with unequal thickness. The dynamic response of built-up structures is influenced by the characteristics of the joints and the damping capacity of such joints has been analyzed by mathematical modeling and experiments. Damping at structural joints is associated with frictional losses caused by micro-slip and kinematics coefficient of friction at the interfaces. Such energy dissipation at various joints has a significant effect in limiting the magnitude of vibration. The free vibration of a beam jointed with rivets of unequal thickness with ratio of 2.0 undergoing a small dynamic deflection in the transverse direction has been studied using the energy approach to evaluate its damping capacity. The results of the theoretical analysis have been compared with the experimental results to verify the authenticity of the work. It has been found that the normal pressure and the micro-slip at the interfaces are the major parameters influencing the damping capacity of jointed riveted structures. The suggested method can be effectively utilized by the designers to fabricate the engineering built-up structures depending on the requirements of the damping capacity.
Conditional versus unconditional mean‐squared prediction errors for Gaussian processes with constant but unknown mean

For prediction in a Gaussian random field, we give an explicit formulation of the conditional mean‐squared prediction error (cmspe). If the prediction method is ordinary kriging, we find that this error in most applications is likely to be very close to the ordinary kriging variance. This is additionally demonstrated based on a case study. Finally, we discuss the difference between these two errors compared to the error introduced by using estimated instead of true covariance parameters. Copyright © 2009 John Wiley & Sons, Ltd.