Miracle-dz/UniFAR-FTUs huggingface dataset:
FAAD: an unsupervised fast and accurate anomaly detection method for a multi-dimensional sequence over data stream

Recently, sequence anomaly detection has been widely used in many fields. Sequence data in these fields are usually multi-dimensional over the data stream. It is a challenge to design an anomaly detection method for a multi-dimensional sequence over the data stream to satisfy the requirements of accuracy and high speed. It is because: (1) Redundant dimensions in sequence data and large state space lead to a poor ability for sequence modeling; (2) Anomaly detection cannot adapt to the high-speed nature of the data stream, especially when concept drift occurs, and it will reduce the detection rate. On one hand, most existing methods of sequence anomaly detection focus on the single-dimension sequence. On the other hand, some studies concerning multi-dimensional sequence concentrate mainly on the static database rather than the data stream. To improve the performance of anomaly detection for a multi-dimensional sequence over the data stream, we propose a novel unsupervised fast and accurate anomaly detection (FAAD) method which includes three algorithms. First, a method called “information calculation and minimum spanning tree cluster” is adopted to reduce redundant dimensions. Second, to speed up model construction and ensure the detection rate for the sequence over the data stream, we propose a method called “random sampling and subsequence partitioning based on the index probabilistic suffix tree. ” Last, the method called “anomaly buffer based on model dynamic adjustment” dramatically reduces the effects of concept drift in the data stream. FAAD is implemented on the streaming platform Storm to detect multi-dimensional log audit data. Compared with the existing anomaly detection methods, FAAD has a good performance in detection rate and speed without being affected by concept drift.
Exploration of an Optimal Two-Dimensional Multi-Core System for Singular Value Decomposition

Singular value decomposition (SVD) has been widely used to identify unique features from a data set in various fields. However, a complex matrix calculation of SVD requires tremendous computation time. This paper improves the performance of a representative one-sided block Jacoby algorithm using a two-dimensional (2D) multi-core system. In addition, this paper explores an optimal multi-core system by varying the number of processing elements in the 2D multi-core system with the same 400MHz clock frequency and TSMC 28nm technology for each matrix-based one-sided block Jacoby algorithm (, , , ). Moreover, this paper demonstrates the potential of the 2D multi-core system for the one-sided block Jacoby algorithm by comparing the performance of the multi-core system with a commercial high-performance graphics processing unit (GPU).
Reference-Reliability as a Concept of Reliability of Change in Times Series Data

The concept of reference-reliability relates variability that is due to change to variability that is due to change and error. It is suitable for deciding whether some suspected change can reliably be differentiated from random fluctuations. This task requires a means by which to measure the process of change at different points in time. Aggregating the data in various ways is used to average out various sources of variation. The variation due to change and/or error is estimated via that part of variation that is not due to individual stability. The many ways to arrange the data yield the possibility to screen them for different kinds of fluctuations. Empirical findings support the usefulness of the coefficient of reference-reliability.
Testing For A Unit Root In A Time Series With A Changing Mean

This study considers testing for a unit root in a time series characterized by a structural change in its mean level. My approach follows the “intervention analysis” of Box and Tiao (1975) in the sense that I consider the change as being exogenous and as occurring at a known date. Standard unit-root tests are shown to be biased toward nonrejection of the hypothesis of a unit root when the full sample is used. Since tests using split sample regressions usually have low power, I design test statistics that allow the presence of a change in the mean of the series under both the null and alternative hypotheses. The limiting distribution of the statistics is derived and tabulated under the null hypothesis of a unit root. My analysis is illustrated by considering the behavior of various univariate time series for which the unit-root hypothesis has been advanced in the literature. This study complements that of Perron (1989), which considered time series with trends.
Spin polarized tunneling through single-crystal GaAs(001) barriers

We investigate spin-dependent transport through an epitaxial GaAs(001) barrier sandwiched between polycrystalline iron films. Electron transport through the barrier is dominated by quantum mechanical tunneling, demonstrated by a nonlinear I–V characteristic, an exponential dependence of the tunneling current on the barrier thickness and the temperature dependence of the current. Though small a clear tunneling magnetoresistance effect proves spin-dependent transport through the Fe–GaAs interface. The small size of the effect and the high-field magnetoresistance suggest that spin–flip scattering plays a decisive role in transport.
Influence of Temperature and Dissolved Oxygen on Nitrogen and Phosphorus Removal of Integrated Bioreactor

An integrated biological membrane sewage treatment device has been designed based on the mechanism of microorganism nitrogen and phosphorus removal and the influence of temperature and dissolved oxygen on nitrogen and phosphorus removal of integrated bioreactor with adoption of this sewage treatment device. The research results shows that the optimal temperature range of microorganism nitrogen and phosphorus removal is 20-30 °C, and the effluent COD removal rate within this range maintains at over 90%; 4 NH N  removal rate is between 95% and 97%. TN removal rate is approximately 81%. In practical production, the internal temperature environment of the sewage reactor should be maintained at above 15 °C, to decrease the inhibition of low-temperature environment on growth and reaction speed of nitrobacteria. In various concentrations of DO in the reactor, there is little change in the effluent COD concentration and effluent COD concentration is influenced by temperature. With the increasing of DO concentration, both effluent TN and TP concentrations present changing features of initially decreasing then increasing. The analysis of the influence of comprehensive dissolved oxygen on microorganism nitrogen and phosphorus removal reveals that when the concentration of DO maintains within the range of 1.0-1.5 mg/L, the sewage purification system can attain a higher nitrogen and phosphorus removal effect.
Group-oriented (t, n) threshold digital signature scheme and digital multisignature

The paper presents group-oriented (t,n) threshold digital signature schemes based on the difficulty of solving the discrete logarithm problem. By employing these schemes, any t out of n users in a group can represent this group to sign the group signature. The size of the group signature and the verification time of the group signature are equivalent to that of an individual digital signature. In other words, the (t, n) threshold signature scheme has the following five properties: (i) any group signature is mutually generated by at least t group members; (ii) the size of the group signature is equivalent to the size of an individual signature; (iii) the signature verification process is simplified because there is only one group public key required; (iv) the group signature can be verified by any outsider; and (v) the group holds the responsibility to the signed message. In addition to the above properties, two of the schemes proposed do not require the assistance of a mutually trusted party. Each member selects its own secret key and the group public key is determined by all group members. Each group member signs a message separately and sends the individual signature to a designated clerk. The clerk validates each individual signature and then combines all individual signatures into a group signature. The (n, n) threshold signature scheme can be easily extended to become a digital multisignature scheme. < >
Multiferroic properties of sputtered BiFeO3 thin films

A cosputtering method was used to deposit BiFeO3 thin films on Pt∕Ti∕SiO2∕Si substrates. It was confirmed as a polycrystalline film with a tetragonal crystal structure in the annealed state. Both Fe2+ and Fe3+ ions were found to coexist in the film. The leakage current density is as low as 10−3A∕cm2 at 120kV∕cm. This sputtered film shows multiferroic properties exhibiting a saturated ferroelectric loop with a large remnant polarization of 37μC∕cm2 and a saturated ferromagnetic loop with saturation magnetization of 21emu∕cm3 at room temperature.
Physical processes in the interstellar medium

Interstellar Matter-- An Overview. Elastic Collisions and Kinetic Equilibrium. Radiative Processes. Excitation. Ionization and Dissociation. Kinetic Temperature. Optical Properties of Grains. Polarization and Grain Alignment. Physical Properties of Grains. Dynamical Principles. Overall Equilibrium. Explosive Motions. Gravitational Motion. Symbols. Index.
Cadmium effects on mineral nutrition of the Cd-hyperaccumulator Pfaffia glomerata

A plant’s ability to survive in a stressful environment is correlated with its nutritional status, which can be affected by cadmium (Cd) uptake. The present study evaluated the influence of Cd on the concentrations and distributions of nutrients in the roots and shoots of the Cd-hyperaccumulator Pfaffia glomerata (Sprengel) Pedersen. Plantlets were cultivated in nutrient solutions containing increasing Cd concentrations during 20 days under greenhouse conditions, and the concentrations of Cd and essential macro- (N, P, K, Ca, Mg and S) and micro- (Zn, Fe, Mn, Cu) elements in the roots and shoots were subsequently determined. Cd did not affect the plant biomass production. Cd accumulation was found to be higher in roots than in shoots, and influenced the distribution of macro and micro elements in those plants. Despite the high phytotoxicity of this element, our results indicated the existence of Cd-tolerance mechanisms in both nutrient uptake and distribution processes that enabled these plants to survive in Cd-contaminated sites.
Correcting high-density hot pixel defects in digital imagers

Based on our extensive research on in-field defect development in digital imagers, we were able to determine that “Hot Pixels” are the main source of defects and their numbers increase at a nearly constant temporal rate (during the camera’s lifetime) and they are randomly distributed spatially (over the camera sensor). Using dark frame analysis, we concluded that a hot pixel can be characterized by a linear function of the exposure time to describe the defect’s dark response. Assuming that the hot pixel behavior remains constant after formation, we present in this paper a novel method for correcting the damage to images caused by a hot pixel, based on estimating its dark response parameters. We performed experiments on a camera with 28 known hot pixels allowing us to compare our correction algorithm to the conventional correction done by interpolating the four neighbors of the defective pixel. We claim that the correction method used should depend on the severity of the hot pixel, on the exposure time, on the ISO, and on the variability of the pixel’s neighbors in the specific image we are correcting. Furthermore, we discuss our new findings in hot pixel behavior that limit the accuracy of defect correction algorithms.
Dual functions of Expansin in cell wall extension and compression during cotton fiber development

Cotton fiber provides a distinct picture of cell wall synthesis. It is an epidermal single-cell extension of Cotton plant seed and undergoes three main stages of development, (1) initiation, (2) elongation and (3) maturation. The fiber initiation characterized by thin primary cell wall formation, which is extended afterward by the action of specific non-enzymatic proteins called Expansins, which promote expansion between cellulose microfibrils by cutting the bridges between cellulose and Hemicellulose residues. The elongation phase followed by a compression phase where the secondary cell wall becomes compact and thickened by the deposition of polysaccharides. The fiber development eventually ends up in the maturation phase, attaining the final maximum length of ∼2.5–3.0 cm. However, the most critical periods of Cotton fiber development are cell wall extension and cellulose deposition. Many studies have focused on the role of Expansins in cell wall elongation, but the significance of expansins in cellulose deposition of the secondary cell wall has barely studied to date. This paper, therefore, is a brief review, which will emphasize the role of Expansin in both cell wall extensibility and polysaccharide deposition during the compression phase. However, the versatile role of Expansin proteins in cellulose deposition and cell wall elongation need a more critical experimental approach.
Stationary axisymmetry electromagnetic fields in the Kerr metric

A procedure for calculating the Debye potential corresponding to a stationary axisymmetric distribution of charges and currents in the Kerr metric is given. The electromagnetic potential is derived by differentiation. The potential of a point charge on the symmetry axis and the value of the charge resulting from the accretion in the case of a charged current loop situated in the equatorial plane are determined with this formalism.
Wintertime Dispersion in a Mountainous Basin at Roanoke, Virginia: Tracer Study.

Abstract During January 1989, five nighttime SF6 tracer experiments were conducted in Roanoke, Virginia. The experiments were designed to help identify and understand the dispersion characteristics of a basin atmosphere during winter stagnation conditions. The basin studied was the Roanoke basin located on the eastern slopes of the Appalachian Mountains. This paper documents this tracer study and gives results from the experiment conducted on the night of 16–17 January 1989. A cold-air pool formed in the basin beginning after the evening transition period and filled to near the elevation of the lowest mountain barrier. A simple model of the ascent rate of the top of this cold-air pool is proposed. A sharp potential temperature jump was present at the top of this fully developed cold-air pool. Vertical measurements of tracer showed the initial ground-level plume to become elevated and ride over the top of the cold-air pool. Horizontal plume spread was enhanced over that expected from turbulent diffusion al.
TECHNOLOGICAL PROBLEMS OF EQUAL CHANNEL ANGULAR PRESSING

Equal channel angular pressing (ECAP) is an effective process to produce materials with increased mechanical properties and no change of billet size. In the present paper the experimental and finite element analysis results of ECAP investigation were obtained. The influ- ence of die geometry and friction condition on irregularity of shear strain field in the cross section of the billet and therefore on mechanical properties distribution was studied. ECAP was shown to be always characterized by irregular shear strain distribution. Depending on die geometry and friction condition that irregularity could be reduced.
3-D Printed Conveyor for Continuous-Mode Cryopreservation of Individual Samples

ix CHAPTER 1. BACKGROUND AND MOTIVATION . 1 1.1. BACKGROUND AND BASIC PRINCIPLES . 1 1.2. CRYOPRESERVATION PROCESS . 1 1.2.1. Cryopreservation Agents . 1 1.2.2. Cooling Profile . 2 1.2.2.1. Cooling Rates . 3 1.2.2.2. Plunge Temperature . 3 1.3. Freezing Devices . 3 1.3. 1. Commercial . 3 1.3. 1.1. Controlled-Rate Freezers . 3 1.3. 1.2. Portability . 5 1.3. 1.3. Freezing Containers . 6 1.3. 2. Published Devices . 7 1.3. 2.1. Cryopreservation Elevator . 7 1.3. 2.2. Positional Cooling Platform Device . 8 1.4. Challenges . 8 1.5. Significance . 9 CHAPTER 2. 3-D PRINTING FOR CRYOPRESERVATION . 10 2.1. OVERVIEW . 10 2.2. INTRODUCTION . 10
Adaptively controlling non-linear systems, using trajectory approximations

The structure underlying most adaptive algorithms is a linear parametrized set. This set either represents the universe of controllers the adaptive algorithm can choose from in order to achieve the control task or it may represent a class of models the adaptive algorithm may exploit to approximate the open-loop plant behaviour. In the latter approach the controller used to close the loop is selected via some non-linear map of the identified model parameters. The emphasis is on approximating the vector field that generates the trajectories of the system. Alternatively we propose to predict the trajectories over a short period of time directly, not indirectly involving a representation of the underlying vector fields. The feasibility of such an approach using a one-step-ahead-type algorithm for both prediction and control is analysed. The scheme is hybrid in that the plant is continuous-time, whilst the control action is implemented in discrete time. The control action is of the model reference type. The algorithm is applied to a class of (non)-linear time-varying systems of a given structure (known relative degree) and possessing a stable inverse. Given input/output measurements only, the algorithm can enforce a desired response within guaranteed error bounds. Robustness properties with respect to partial state measurement (e.g. neglecting parasitic dynamics) and violation of the stable inverse assumption are investigated.
The Structure of Semisimple Symmetric Spaces

A semisimple symmetric space can be defined as a homogeneous space G/H, where G is a semisimple Lie group, H an open subgroup of the fixed point group of an involutive automorphism of G. These spaces can also be characterized as the affine symmetric spaces or pseudo-Riemannian symmetric spaces or symmetric spaces in the sense of Loos [4] with semisimple automorphism groups [3, 4]. The connected semisimple symmetric spaces are all known: they have been classified by Berger [2] on the basis of Cartan's classification of the Riemannian symmetric spaces. However, the list of these spaces is much too long to make a detailed case by case study feasible. In order to do analysis on semisimple symmetric spaces, for example, one needs a general structure theory, just as in the case of Riemannian symmetric spaces and semisimple Lie groups.
Generating Data with Identical Statistics but Dissimilar Graphics

The Anscombe dataset is popular for teaching the importance of graphics in data analysis. It consists of four datasets that have identical summary statistics (e.g., mean, standard deviation, and correlation) but dissimilar data graphics (scatterplots). In this article, we provide a general procedure to generate datasets with identical summary statistics but dissimilar graphics by using a genetic algorithm based approach.
Perturbation and stability analyses of nonlinear buoyant flow in mushy layers

We consider the problem of weakly nonlinear buoyant flow and its stability in horizontal dendrite layers, often referred to as mushy layers, during solidification of binary alloys. A mushy layer is a layer that is formed adjacent to the solidification front and is composed of both solid dendrites and melt. Understanding the convective flow driven by the buoyancy force within the mushy layer is known to be important for proper production of high-quality solidified alloy. In the present study, no restriction is imposed on the thickness of the mushy layer, and a number of simplifying assumptions made in previous related nonlinear analyses are lifted here in order to determine the results on the basis of a more realistic model. Using perturbation and stability analyses and some numerical approaches, we determine the steady stable solutions to the weakly nonlinear problem under a certain range of the parameter values where such analyses are valid. The relevant parameters for the present problem are the Rayleigh number representing the buoyancy, the Stefan number representing the latent heat of solidification, a concentration ratio parameter representing the composition of the solid dendrites in the mushy layer, and the far-field temperature parameter. We found, in particular, that depending on the range of parameter values, stable convective flow is possible in the form of subcritical or supercritical down-hexagons, with down-flow at the cells’ centers and up-flow at the cells’ boundaries, and subcritical or supercritical up-hexagons, with up-flow at the cells’ centers and down-flow at the cells’ boundaries, supercritical rectangles, supercritical squares and supercritical rolls.
A design method for minimum-inductance planar magnetic-resonance-imaging gradient coils considering the pole-piece effect

A design method for a planar gradient coil, which has minimum inductance with the presence of a pole piece around the gradient coil, is proposed. In magnetic-resonance-imaging systems using permanent magnets, magnetic materials of high permeability are used for the pole piece so that the magnetic field can be as uniform as possible. Owing to the high permeability of the pole piece, the gradient field produced by the conventional planar gradient coil deviates from the desired one. We have modelled the pole-piece effects as a mirror current for design of a minimum-inductance gradient coil. A finite-element method is applied to find the optimum amplitude of the mirror current that makes the magnetic field most similar to the real field. With the mirror-current model, we have derived the current-density function that gives the minimum inductance with the presence of the pole piece.
On the controllability of quantum‐mechanical systems

The systems‐theoretic concept of controllability is elaborated for quantum‐mechanical systems, sufficient conditions being sought under which the state vector ψ can be guided in time to a chosen point in the Hilbert space H of the system. The Schrodinger equation for a quantum object influenced by adjustable external fields provides a state‐evolution equation which is linear in ψ and linear in the external controls (thus a bilinear control system). For such systems the existence of a dense analytic domain Dω in the sense of Nelson, together with the assumption that the Lie algebra associated with the system dynamics gives rise to a tangent space of constant finite dimension, permits the adaptation of the geometric approach developed for finite‐dimensional bilinear and nonlinear control systems. Conditions are derived for global controllability on the intersection of Dω with a suitably defined finite‐dimensional submanifold of the unit sphere SH in H. Several soluble examples are presented to illuminate th.
A new type of mode power characteristics of extremely short external cavity semiconductor laser

In this paper, the total output power features and the mode power characteristics of the extremely short external cavity semiconductor lasers (ESECSLs) have been investigated experimentally and theoretically, and a new type of variation of ESECSL's mode power is reported. The results show that with the variation of the external cavity length at the order of lasing wavelength, the total output power and the mode power of ESECSLs will hop periodically, and the different mode presents diverse power characteristics. Especially, some modes, locating at the material gain center of ESECSL, present unique double peak characteristics. Moreover, the primarily theoretical simulations and the physics explanation about these double peak characteristics have been given. The theoretical simulation results agree well with the experimental results. These new type characteristics of ESECSL's mode power may be useful in improving the sensitivity of all-optical sensors and developing the new type of optical data read-write head.