Miracle-dz/UniFAR-FTUs huggingface dataset:
Time series forecasting with neural networks: a comparative study using the air line data

This case‐study fits a variety of neural network (NN) models to the well‐known air line data and compares the resulting forecasts with those obtained from the Box–Jenkins and Holt–Winters methods. Many potential problems in fitting NN models were revealed such as the possibility that the fitting routine may not converge or may converge to a local minimum. Moreover it was found that an NN model which fits well may give poor out‐of‐sample forecasts. Thus we think it is unwise to apply NN models blindly in ‘black box’ mode as has sometimes been suggested. Rather, the wise analyst needs to use traditional modelling skills to select a good NN model, e.g. to select appropriate lagged variables as the ‘inputs’. The Bayesian information criterion is preferred to Akaike's information criterion for comparing different models. Methods of examining the response surface implied by an NN model are examined and compared with the results of alternative nonparametric procedures using generalized additive models and projection pursuit regression. The latter imposes less structure on the model and is arguably easier to understand.
Two-Dimensional RC/SW Constrained Codes: Bounded Weight and Almost Balanced Weight

In this work, we study two types of constraints on two-dimensional binary arrays. Given <inline-formula> <tex-math notation="LaTeX">$p\in [{0,1}],\epsilon \in [{0,1/2}]$ </tex-math></inline-formula>, we study 1) the <inline-formula> <tex-math notation="LaTeX">$p$ </tex-math></inline-formula>-bounded constraint: a binary vector of size <inline-formula> <tex-math notation="LaTeX">$n$ </tex-math></inline-formula> is said to be <inline-formula> <tex-math notation="LaTeX">$p$ </tex-math></inline-formula>-bounded if its weight is at most <inline-formula> <tex-math notation="LaTeX">$pn$ </tex-math></inline-formula>, and 2) the <inline-formula> <tex-math notation="LaTeX">$\epsilon $ </tex-math></inline-formula>-balanced constraint: a binary vector of size <inline-formula> <tex-math notation="LaTeX">$n$ </tex-math></inline-formula> is said to be <inline-formula> <tex-math notation="LaTeX">$\epsilon $ </tex-math></inline-formula>-balanced if its weight is within <inline-formula> <tex-math notation="LaTeX">$\big [(1/2-\epsilon)n, (1/2+\epsilon)n\big]$ </tex-math></inline-formula>. Such constraints are crucial in several data storage systems, those regard the information data as two-dimensional (2D) instead of one-dimensional (1D), such as the crossbar resistive memory arrays and the holographic data storage. In this work, efficient encoding/decoding algorithms are presented for binary arrays so that the weight constraint (either <inline-formula> <tex-math notation="LaTeX">$p$ </tex-math></inline-formula>-bounded constraint or <inline-formula> <tex-math notation="LaTeX">$\epsilon $ </tex-math></inline-formula>-balanced constraint) is enforced over every row and every column, regarded as 2D row-column (RC) constrained codes; or over every window (where each window refers to as a subarray consisting of consecutive rows and consecutive columns), regarded as 2D sliding-window (SW) constrained codes. While low-complexity designs have been proposed in the literature, mostly focusing on 2D RC constrained codes where <inline-formula> <tex-math notation="LaTeX">$p=1/2$ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$\epsilon =0$ </tex-math></inline-formula>, this work provides efficient coding methods that work for both 2D RC constrained codes and 2D SW constrained codes, and more importantly, the methods are applicable for arbitrary values of <inline-formula> <tex-math notation="LaTeX">$p$ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$\epsilon $ </tex-math></inline-formula>. Furthermore, for certain values of <inline-formula> <tex-math notation="LaTeX">$p$ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$\epsilon $ </tex-math></inline-formula>, we show that, for sufficiently large array size, there exists linear-time encoding/decoding algorithm that incurs at most one redundant bit.
Use of airborne remote sensing to detect riverside Brassica rapa to aid in risk assessment of transgenic crops

High resolution descriptions of plant distribution have utility for many ecological applications but are especially useful for predictive modeling of gene flow from transgenic crops. Difficulty lies in the extrapolation errors that occur when limited ground survey data are scaled up to the landscape or national level. This problem is epitomized by the wide confidence limits generated in a previous attempt to describe the national abundance of riverside Brassica rapa (a wild relative of cultivated rapeseed) across the United Kingdom. Here, we assess the value of airborne remote sensing to locate B. rapa over large areas and so reduce the need for extrapolation. We describe results from flights over the river Nene in England acquired using Airborne Thematic Mapper (ATM) and Compact Airborne Spectrographic Imager (CASI) imagery, together with ground truth data. It proved possible to detect 97% of flowering B. rapa on the basis of spectral profiles. This included all stands of plants that occupied >2m square (>5 plants), which were detected using single-pixel classification. It also included very small populations (<5 flowering plants, 1-2m square) that generated mixed pixels, which were detected using spectral unmixing. The high detection accuracy for flowering B. rapa was coupled with a rather large false positive rate (43%). The latter could be reduced by using the image detections to target fieldwork to confirm species identity, or by acquiring additional remote sensing data such as laser altimetry or multitemporal imagery.
Orientation dependence of optical gain in zincblende-GaN strained-quantum-well lasers

Optical gains in zincblende-GaN strained-quantum-well (QW) lasers are analyzed theoretically for various crystal orientations. Valence subbands are calculated based on the 6/spl times/6 Luttinger-Kohn model. It is found that the gains in zincblende-GaN strained-QW lasers with [110] orientation are much higher than those in wurtzite-GaN lasers with (0001) orientation.
Frequency-domain Controller Design for Switched Systems

Automatic Control Laboratory, Ecole Polytechnique F´ed´erale de Lausanne (EPFL), 1015 Lausanne, SwitzerlandAbstractIn a recent work, a new framework to design controllers using frequency-domain data is proposed. The method is basedon the shaping of the open-loop transfer function in the Nyquist diagram with constraints on the robustness margins andperformance in terms of the crossover frequency. By solving a linear programming problem, it is possible to design ﬁxed-orderlinearly parameterized controllers for stable SISO LTI multi-model systems. In this paper, it is proposed to extend this designframework to guarantee quadratic stability of certain classes of switched systems by adding new linear constraints based onthe phase diﬀerence of the characteristic polynomials of the closed-loop subsystems. These new linear constraints can also beused to guarantee quadratic stability of certain classes of LPV systems. Some simulation examples are provided to illustratethe proposed approach.Key words: Switched systems, Nyquist diagram, Linear programming, Quadratic stability, LPV systems.
Donor derived hematopoietic stem cell niche transplantation facilitates mixed chimerism mediated donor specific tolerance

Compelling experimental evidence confirms that the robustness and longevity of mixed chimerism (MC) relies on the persistence and availability of donor-derived hematopoietic stem cell (HSC) niches in recipients. Based on our prior work in rodent vascularized composite allotransplantation (VCA) models, we hypothesize that the vascularized bone components in VCA bearing donor HSC niches, thus may provide a unique biologic opportunity to facilitate stable MC and transplant tolerance. In this study, by utilizing a series of rodent VCA models we demonstrated that donor HSC niches in the vascularized bone facilitate persistent multilineage hematopoietic chimerism in transplant recipients and promote donor-specific tolerance without harsh myeloablation. In addition, the transplanted donor HSC niches in VCA facilitated the donor HSC niches seeding to the recipient bone marrow compartment and contributed to the maintenance and homeostasis of stable MC. Moreover, this study provided evidences that chimeric thymus plays a role in MC-mediated transplant tolerance through a mechanism of thymic central deletion. Mechanistic insights from our study could lead to the use of vascularized donor bone with pre-engrafted HSC niches as a safe, complementary strategy to induce robust and stable MC-mediated tolerance in VCA or solid organ transplantation recipients.
Annotated Dataset for Anomaly Detection in a SDN infraestructure

Software-Defined Network (SDN) is an emerging architecture which objective is to re- duce the limitations of traditional IP networks by decoupling the network tasks performed on each device in certain planes by controlling and managing the whole network from a centralized location. However, this centralization also introduces new inefficiencies and vulnerabilities, such as those related to southbound and northbound controller interfaces, which often negatively affect security. In the past years, Machine Learning (ML) tech- niques have been implemented in SDN architectures to protect networks and solve security problems but sometimes it is difficult to obtain the right characteristics in real time. In this paper, we introduce a flow-based anomaly detection system in which the controller itself is in charge of receiving, analyzing and classifying the traffic by extracting a group of flow features.
Dual-Frequency High-Gain Horizontally Polarized Omnidirectional Leaky-Wave Antenna

This article presents a dual-frequency high-gain horizontally polarized omnidirectional (HPO) antenna with the leaky-wave concept. The first and second modes of the half-width microstrip line (HWMSL) are investigated and it is found that these two modes can be employed to design a dual-frequency HPO bidirectional leaky-wave antenna (Bi-LWA). Moreover, it is revealed that the first mode would be unexpectedly excited at the operation frequency of the second mode (<inline-formula> <tex-math notation="LaTeX">$f_{2}$ </tex-math></inline-formula>). Therefore, shorting pins are periodically loaded underneath the HWMSL, so as to create a stopband for the first mode at <inline-formula> <tex-math notation="LaTeX">$f_{2}$ </tex-math></inline-formula>. With resort to the transmission line model of this pin-loaded HWMSL, the lower and upper cut-off frequencies of the stopband are explicitly derived. Under the guidance of these formulas, one can effectively control the position of the stopband, so as to suppress the undesired mode at maximum. The internal electric fields of a uniform and a pin-loaded HWMSL Bi-LWA are extracted, illustrating that the first mode component has been efficiently reduced at <inline-formula> <tex-math notation="LaTeX">$f_{2}$ </tex-math></inline-formula>. A prototype is finally realistically fabricated and measured for verification. The simulations and measurements both show that the desired HPO radiation patterns are realized at the designed two frequencies.
The Quest Language and System

tuples An abstract type is obtained by a tuple type which contains a type and a set of constants and operations over that type. Let T = Tuple A::TYPE a:A f(x:A):Int end; ‡ Let T::TYPE = Tuple A::TYPE a:A f(x:A):Int end This abstract type can be implemented by providing a type, a value of that type, and an operation from that type to Int:
Content Caching Based on Popularity and Priority of Content Using seq2seq LSTM in ICN

Efficient content caching is essential to address the explosive growth of multimedia contents and most works on content cache placement have been proposed mainly based on the popularity of content. Since the priority of content is also an important attribute of content, we consider both popularity and priority of content together for content caching in information-centric networking (ICN). We define weighted delivery cost of content as content delivery cost multiplied by a weighted sum of popularity and priority of the content. Then, we formulate optimized content cache placement problem to minimize weighted content delivery cost for all content requests in a hierarchical network architecture with multi-access edge computing (MEC) and software-defined networking (SDN) controller. Average quality of experience (QoE), i.e., average content delivery cost, for contents with each priority is imposed as constraint. The number of content requests is predicted based on seq2seq long short-term memory (LSTM) model in MECs and this is delivered to SDN controller. Then, SDN controller obtains predicted popularity of contents and decides content placement in MECs and core routers by solving the content cache placement optimization problem based on binary particle swarm optimization (BPSO). Performance of the proposed content caching scheme is compared with conventional popularity-based, popularity prediction-based, and popularity prediction-based optimization schemes, from the aspect of QoE satisfaction ratio, average cost, weighted average cost, total cost, and weighted total cost. Numerical results show the effectiveness of the proposed scheme at caching content with high priority efficiently, at the expense of caching content with low priority.
Evaluation and Correction of $B_{1}^+$-Based Brain Subject-Specific SAR Maps Using Electrical Properties Tomography

The specific absorption rate (SAR) estimates the amount of power absorbed by the tissue and is determined by the electrical conductivity and the E-field. Conductivity can be estimated using Electric Properties Tomography (EPT) but only the E-field component associated with <inline-formula><tex-math notation="LaTeX">$B_{1}^+$</tex-math></inline-formula> can be deduced from <inline-formula><tex-math notation="LaTeX">$B_{1}$</tex-math></inline-formula>-mapping. Herein, a correction factor was calculated to compensate for the differences between the actual SAR and the one obtained with <inline-formula><tex-math notation="LaTeX">$B_{1}^+$</tex-math></inline-formula>. Numerical simulations were performed for 27 head models at <inline-formula><tex-math notation="LaTeX">$128 \,\mathrm{M}\mathrm{Hz}$</tex-math></inline-formula>. Ground-truth local-SAR and 10g-SAR (SAR<sub>GT</sub>) were computed using the exact electrical conductivity and the E-field. Estimated local-SAR and 10g-SAR (SAR<sub>EST</sub>) were computed using the electrical conductivity obtained with a convection-reaction EPT and the E-field obtained from <inline-formula><tex-math notation="LaTeX">$B_{1}^+$</tex-math></inline-formula>. Correction factors (CFs) were estimated for gray matter, white matter, and cerebrospinal fluid (CSF). A comparison was performed for different levels of signal-to-noise ratios (SNR). Local-SAR/10g-SAR CF was 3.08 <inline-formula><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0/06 / 2.11 <inline-formula><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0.04 for gray matter, 1.79 <inline-formula><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0/05 / 2.06 <inline-formula><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0.04 for white matter, and 2.59 <inline-formula><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0/05 / 1.95 <inline-formula><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0.03 for CSF. SAR<sub>EST</sub> without CF were underestimated (ratio across [<inline-formula><tex-math notation="LaTeX">$\infty$</tex-math></inline-formula> - 25] SNRs: 0.52 <inline-formula><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0.02 for local-SAR; 0.55 <inline-formula><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0.01 for 10g-SAR). After correction, SAR<sub>EST</sub> was equivalent to SAR<sub>GT</sub> (ratio across [<inline-formula><tex-math notation="LaTeX">$\infty$</tex-math></inline-formula> - 25] SNRs: 0.97 <inline-formula><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0.02 for local-SAR; 1.06 <inline-formula><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0.01 for 10g-SAR). SAR maps based on <inline-formula><tex-math notation="LaTeX">$B_{1}^+$</tex-math></inline-formula> can be corrected with a correction factor to compensate for potential differences between the actual SAR and the SAR calculated with the E-field derived from <inline-formula><tex-math notation="LaTeX">$B_{1}^+$</tex-math></inline-formula>.
Optimising UAV Data Acquisition and Processing for Photogrammetry: A Review

Unmanned aerial vehicles (UAVs) are used to acquire measurement data for an increasing number of applications. Photogrammetric studies based on UAV data, thanks to the significant development of computer vision techniques, photogrammetry, and equipment miniaturization, allow sufficient accuracy for many engineering and non-engineering applications to be achieved. In addition to accuracy, development time and cost of data acquisition and processing are also important issues. The aim of this paper is to present potential limitations in the use of UAVs to acquire measurement data and to present measurement and processing techniques affecting the optimisation of work both in terms of accuracy and economy. Issues related to the type of drones used (multi-rotor, fixed-wing), type of shutter in the camera (rolling shutter, global shutter ), camera calibration method (pre-calibration, self-calibration), georeferencing method (direct, indirect), technique of measuring the external images orientation parameters (RTK, PPK, PPP), flight design methods and the type of software used were analysed.
Approximate expressions for generalized Green's functions

The traditional Green's function has been widely used to analyze the behavior of surface acoustic wave (SAW) devices for many years because of its clear physical meaning and its ability to model all propagation modes. Simplifications introduced in its derivation, however, cause it to ignore some important effects such as mass loading due to surface electrodes. The generalized Green's function method is able to characterize these effects, but its computation is numerically intensive and complex. In this paper, we present a method of deriving approximate expressions similar in concept to Ingebrigtsen's approximation that can be applied to all sixteen elements of the generalized Green's functions. Results are shown for two representative substrates.
User-Preference-Learning-Based Proactive Edge Caching for D2D-Assisted Wireless Networks

This work investigates proactive edge caching for device-to-device (D2D)-assisted wireless networks, where user equipment (UE) can be selected as caching nodes to assist content delivery to reduce the content transmission latency. In doing so, there are two challenges: 1) how to precisely get the user’s preference to cache the proper contents at UEs and 2) how to replace the contents cached at UEs when there are new popular contents emerging. To address these, we develop a user preference learning-based proactive edge caching (UPL-PEC) strategy. In the strategy, we first propose a novel context and social-aware user preference learning method to precisely predict user’s dynamic preferences by jointly exploiting the context correlation among different contents, the influence of social relationships and the time-sequential patterns of user’s content requests. Specifically, the bidirectional long short-term memory networks are adopted to capture the time-sequential patterns of the user’s content requests. And, the graph convolutional networks are developed to capture the high-order similarity representation among different contents from the constructed content graph. To learn the social influence representation, an attention mechanism is designed to generate the social influence weights to users with different social relationship. Based on the learned user preference, a proactive edge caching architecture is proposed to integrate the offline caching content placement and the online caching content replacement policy to continuously cache the popular contents at UEs. Simulation results show that the proposed UPL-PEC strategy outperforms the existing similar caching strategies at about 3.13%–4.62% in terms of the average content transmission latency.
Particle orbits in a rotating liquid

Monodisperse latex microspheres ranging in size from submicrometer to several micrometers in diameter can be prepared in the laboratory. The uniformity of diameter is important for instrument calibration and other applications. However it has proved very difficult to manufacture commercial quantities of mondisperse latex microspheres with diameters larger than about 3 micrometers owing to buoyancy and sedimentation effects. In an attempt to eliminate these effects NASA sponsored a Space Shuttle experiment called the Monodisperse Latex Reactor (MLR) to produce these monodisperse microspheres in larger sizes in microgravity. Results have been highly successful. Using technology gained from this space experiment, a ground-based rotating latex reactor has been fabricated in an attempt to minimize sedimentation without using microgravity. The entire reactor cylinder is rotated about a horizontal axis to keep the particles in suspension. In this paper we determine the motion of small spherical particles under gravity, in a viscous fluid rotating uniformly about a horizontal axis. The particle orbits are approximately circles, with centres displaced horizontally from the axis of rotation. Owing to net centrifugal buoyancy, the radius of the circles increases (for heavy particles) or decreases (for light particles) with time, so that the particles gradually spiral inward or outward. For a large rotation rate, the particles spiral outwards or inwards too fast, while for a small rotation rate, the displacement of the orbit centre from the rotation axis is excessive in relation to the reactor radius. We determine the rotation rate that maximizes the fraction of the reactor cross-section area that contains particles that will not spiral out to the wall in the experimental time (for heavy particles), or that have spiralled in without hitting the wall (for light particles). Typically, the rate is close to 1 r.p.m. , and design rotation rate ranges should span this value.
Convergence analysis of asynchronous iterations with stochastic delays

The authors present a general linear model of asynchronous iterations, the communication delays of which are stochastic with a Markovian character. This model allows static or dynamic allocation of the iterate vector components to processors. It also permits simultaneous updating of the same vector component by multiple processors. Sufficient conditions under which the model of asynchronous iterations converges in the second moment (and in the mean) to the sought resolution are provided. For the specialization of the Markov case when the communication delays are independent and identically distributed, the authors provide sufficient conditions for convergence in the second moment and necessary and sufficient conditions for convergence in the mean. <<ETX>>