Miracle-dz/UniFAR-FTUs huggingface dataset:
Cooperative localization of UAV based on information synchronization

Information synchronization is the key technology of multi-UAV in formation flight. Based on the linear update law, this paper develops a general analytical solution of synchronization for a ring communication topological structure. Considering the fact that GPS is vulnerable to fail in some circumstances which may lead to that the localization of the UAV cannot continue, we propose a localization method by other members' measurements in the UAV team. First, we assume that these UAVs construct a ring communication topological structure and all the units in the network can respectively obtain the position information of the UAV by measuring the relative range and the azimuth from the UAV. Next, the information is synchronized in the ring communication network and it converges to a same value. Finally, the data is communicated to the UAV whose GPS receiver works improperly so that the UAV is capable of continuing the navigation task. Simulation results in Matlab/Simulink show the effectiveness of the proposed approach.
Spectral analysis of LMC X-2 with XMM/Newton: unveiling the emission process in the extragalactic Z-source.

Aims. We present the results of the analysis of an archival observation of LMC X-2 performed with XMM/Newton. The spectra taken by high-precision instruments have never been analyzed before. Methods. We find an X-ray position for the source that is inconsistent with the one obtained by ROSAT, but in agreement with the Einstein position and that of the optical counterpart. The correlated spectral and timing behaviour of the source suggests that the source is probably in the normal branch of its X-ray color-color diagram. The spectrum of the source can be fitted with a blackbody with a temperature 1.5 keV plus a disc blackbody at 0.8 keV. Photoelectric absorption from neutral matter has an equivalent hydrogen column of 4 $\times$ 10 20 cm -2 . An emission line, which we identify as the O VIII Lyman- α line, is detected, while no feature due to iron is detected in the spectrum. Results. We argue that the emission of this source can be straightforwardly interpreted as the sum of the emission from a boundary layer between the NS and the disc and a blackbody component coming from the disc itself. Other canonical models that are used to fit Z-sources do not give a satisfactory fit to the data. The detection of the O VIII emission line (and the lack of detection of lines in the iron region) can be due to the fact that the source lies in the Large Magellanic Cloud.
Mode-Selective Absorption and All-Optical Control Between Two Transverse Modes on Silicon-on-Insulator

Mode-selective absorption is realized by designing the ridge waveguide structure on silicon-on-insulator combined with two metal titanium (Ti) strips located on the two waveguide edges. The TE1 mode can be much easier to permeate the waveguide edges by designing the waveguide structure carefully. Therefore, the overlap between the TE0 and TE1 modes is reduced in the cross section and then the TE1 mode can be absorbed selectively by Ti strips. According to the opto-thermal effect, the refractive index of the waveguide will increase when the temperature rises. As a result, this waveguide structure can achieve all-optical control between two transverse modes with compact structure and low power consumption. As an example, a novel all-optical switch based on the proposed waveguide structure and Bragg grating was designed and numerically studied. We think the proposed structure may give a new way for all-optical control between two transverse modes, especially for the applications in the integrated mode division multiplexing systems.
Converter-less MPPT for rural area applications

A popular method to extract maximum power from a solar PV array is the direct connection of a DC/DC converter to the PV array. It is known as Maximum Power Point Tracking (MPPT) technique. In this approach, the PV array is perturbed at a fractional voltage and few tens of kHz frequency. Drawbacks in this approach of maximum power extraction include oscillations in the DC voltage, reduced conversion efficiency and frequent maintenance of the converters (owing to the frequent failure of electrolytic capacitor), which makes it unsuitable to rural area PV applications. This paper proposes Dynamic PV array (DPVA) approach for extracting maximum power from PV array. In this approach, a switch-network of semiconductor switches or electrical relays is integrated into the PV array to choose a matching-configuration for the load. The absence of high-frequency operation, oscillations in the DC voltage and power processing stages are some inherent advantages of this approach. This paper presents a procedure to design a specific size Dynamic PV array, such that, it produces MPP or close to MPP power at all load conditions. Further, a mathematical relationship between the size of DPVA and the Minimum Output Power (MOP) it can produce is derived. Simulations and a six-module experimental tests are conducted to validate the derived relation.
Real-Time Quantitative PCR

Those who have worked in the field of quantitative polymerase chain reaction (PCR) since the early 1990s have accepted many of the tedious aspects of the early assays as routine. Difficulties associated with early quantitative PCR techniques included: (i) ensuring that the PCR was within the linear range of amplification (that portion where the PCR signal is directly proportional to the input copy number) and (ii) finding a suitable method to detect the product once linear amplification was achieved. To ensure linearity, researchers would amplify serial dilutions of cDNA (1) or alter the amplification cycle for each gene (2). Others would add a competitor template (3), perform limiting dilution assays (4), or use a PCR mimic with a similar primer sequence that would be coamplified along with the product (5). Detection of the amplicon generally resorted to running gels and DNA detection using a stain, radioactivity, or probe. For those who have converted to using real-time quantitative PCR, the old days are but a memory. In real-time PCR, worrying about linear amplification, running gels, working with radioactivity, and gathering numbers are a thing of the past. The ability to generate data within a 2to 3-h period is now a reality. Other advantages of real-time PCR include enhanced sensitivity, high throughput, use of a closed-tube system, reduced variation, the ability to simultaneously multiplex reactions, and lack of post-PCR manipulations. The technology to detect PCR products in real time, i.e., during the reaction, has been available for more than 5 years, but has seen a dramatic increase in use over the past 2 years. A Medline search using the key words TaqMan or real-time and PCR yielded 19 citations in 1996, 28 citations in 1997, and 52, 157, and 409 citations in 1998, 1999, and 2000, respectively. At the time of this writing, there were 551 citations in 2001 (Fig. 1). Various manufacturers are touting realtime PCR instrumentation and affiliated technology
Wheat Brassinosteroid-Insensitive1 (TaBRI1) Interacts with Members of TaSERK Gene Family and Cause Early Flowering and Seed Yield Enhancement in Arabidopsis

Brassinosteroids (BRs) hormones are important for plant growth, development and immune responses. They are sensed by the transmembrane receptor kinase Brassinosteroid-Insensitive 1 (BRI1) when they bind to its extracellular Leu-rich repeat (LRR) domain. We cloned and characterized the TaBRI1 from T. aestivum and raised overexpression transgenics in Arabidopsis to decipher its functional role. TaBRI1 protein consists of a putative signal peptide followed by 25 leucine rich repeats (LRR), a transmembrane domain and a C-terminal kinase domain. The analysis determined the interaction of TaBRI1 with five members of the wheat Somatic Embryogenesis Receptor Kinase (TaSERKs) gene family (TaSERK1, TaSERK2, TaSERK3, TaSERK4 and TaSERK5), at the plasma membrane. Furthermore, overexpression of TaBRI1 in Arabidopsis leads to the early flowering, increased silique size and seed yield. Root growth analysis of TaBRI1 overexpressing transgenic plants showed hypersensitivity to epi-brassinolide (epi-BL) hormone in a dose-dependent manner. Interestingly, transgenic Arabidopsis plants show thermotolerance phenotype at the seedling stages as revealed by chlorophyll content, photosystem II activity and membrane stability. The transcriptome profiling on the basis of microarray analysis indicates up-regulation of several genes related to brassinosteroid signaling pathway, abiotic stress response, defense response and transcription factors. These studies predict the possible role of TaBRI1 gene in plant growth and development imparting tolerance to thermal stress.
Best-scored Random Forest Density Estimation

This paper presents a brand new nonparametric density estimation strategy named the best-scored random forest density estimation whose effectiveness is supported by both solid theoretical analysis and significant experimental performance. The terminology best-scored stands for selecting one density tree with the best estimation performance out of a certain number of purely random density tree candidates and we then name the selected one the best-scored random density tree. In this manner, the ensemble of these selected trees that is the best-scored random density forest can achieve even better estimation results than simply integrating trees without selection. From the theoretical perspective, by decomposing the error term into two, we are able to carry out the following analysis: First of all, we establish the consistency of the best-scored random density trees under $L_1$-norm. Secondly, we provide the convergence rates of them under $L_1$-norm concerning with three different tail assumptions, respectively. Thirdly, the convergence rates under $L_{\infty}$-norm is presented. Last but not least, we also achieve the above convergence rates analysis for the best-scored random density forest. When conducting comparative experiments with other state-of-the-art density estimation approaches on both synthetic and real data sets, it turns out that our algorithm has not only significant advantages in terms of estimation accuracy over other methods, but also stronger resistance to the curse of dimensionality.
Influence of Maximum Current Control Strategy on Torque Ripple in BLDC Motor

Brushless dc motors are voltage source inverter (VSI) fed permanent magnet motors which are popularly known for their faster dynamics, high efficiency, and low maintenance. The dynamics of the motor is predominantly influenced by the type of controller employed in the control loop. Faster dynamics and precise control of BLDC motors is usually achieved by employing hysteresis current controllers. The current sensed either from the DC Link or from the phases of the motor is employed for the control. This paper brings out the effects of these current sensing strategies on torque ripple and switching frequency. It also proposes methods to eliminate the nonlinearities in computing Maximum of Phase Currents by employing micro-controllers.
Validation of Ultrasonography for Assessment of Gastric Emptying Time in Healthy Cats by Radionuclide Scintigraphy

Background The prevalence of gastric emptying (GE) disorders in cats is unknown due to lack of clinically applicable diagnostic tests. Objectives The principal aim of this study was to assess correlation between scintigraphic and ultrasonographic measurements of GE time (GET) in healthy cats. Additionally, variability of ultrasonographic GET, and correlation between scintigraphy and ultrasonographic parameters of gastric motility were evaluated. Animals Eight healthy domestic shorthair cats. Methods Prospective study. Scintigraphic GET was determined using a solid test meal containing 4 mCi 99mTc‐mebrofenin. Each cat had 3 separate ultrasonographic assessments of GE, performed independent of scintigraphic assessment, after solid test meal consumption. The motility index (MI) of antral contractions was plotted against time and time for each fraction of the area under the MI curve determined. Ultrasonographic GET and MI were correlated to scintigraphic GET. Results Scintigraphic GET (mean ± SD) for 25, 50, and 75% GE was 103 ± 32 minutes, 196 ± 45 minutes, and 288 ± 62 minutes, whereas sonographic GET for 25, 50, and 75% GE was 106 ± 13 minutes, 203 ± 19 minutes, and 305 ± 27 minutes. There was good correlation between scintigraphic and sonographic GET (r = 0.72–0.82) at 45–90% fractional GE and between scintigraphic GET and time of corresponding MI curve fraction (r = 0.78–0.86) at 40–90% fraction of the MI curve. There was moderate intraindividual variability for sonographic GET and MI curve fraction times as well as significant variation among individuals. Conclusions and clinical importance Ultrasonography is a valid alternative to scintigraphy for assessment of solid‐phase GE and allows assessment of postprandial gastric motility in healthy cats.
Generalized Perona-Malik Equation Based on Entropy Maximization

This paper presents a new multiscale filter based on a relatively new entropy manipulation method. The method inspires using a generalized neighborhood operation, which updates all the pixels inside the neighborhood window in such a way that the spatial entropy inside the neighborhood window is increased. The interesting similarity between the new proposed filter and Perona-Malik’s filter encourages considering it as a generalization to the Perona-Malik equation. The new proposed filter is compared with the Perona-Malik filter and the results show that the new method outperforms PeronaMalik method.
Small-Signal Modelling and Control of a High Voltage Gain Dual Input Boost DC-DC Converter

This paper presents the small-signal model of single voltage multiplier high voltage gain dual input boost DC-DC converter. The model is developed with parasitic parameters by the state space averaging technique followed by small-signal linearization. For this nonlinear and non-minimum phase converter an inner current loop and outer voltage loop control strategy with PI and compensators are designed in MATLAB. Simulation results corresponding to a step load change between 50 % and full load are presented which ensure proper voltage regulation by controlling the duty cycle of switching the two sources.
User Modeling for Churn Prediction in E-Commerce

In the domain of e-commerce, acquiring a new customer is generally more expensive than keeping the existing ones. A successful prediction of churn of a specific customer provides an opportunity to change his/her decision to leave. In this paper, we propose a novel complex user model focused on the user churn intent prediction. The idea of our model is based on composing of multiple sets of features representing user's interaction with the web application. The performance of our model is evaluated indirectly by the prediction of churn, using real data from online retailers. The results show that the prediction using the proposed model outperforms the churn prediction based on baseline models across two domains.
Sum Rate of Massive MIMO Systems Deploying Uniform Circular Planar Array Base Station Antenna

We consider the sum rate of massive multiple input multiple output (MIMO) systems where the base station (BS) antenna configuration is uniform circular planar array (UCPA). The channel considered is line-of-sight (LOS) governed by the antenna steering vector of each user. The user azimuth and elevation angles are assumed independent and uniformly distributed. The BS performs maximum ratio transmission (MRT) beamforming due to its low complexity and acceptable performance for low to moderate signal-to-noise ratio (SNR). The sum rate performance is then analyzed and compared to the upper bound sum rate obtained by assuming favorable propagation in massive MIMO. It is shown that using a larger amount of antennas increases the slope of the sum rate curve.
A Maximum Power Point Tracking Technique for PV Under Partial Shading Condition

Tracking the Maximum Power Point (MPP) of Photovoltaic (PV) modules is very important to increase the utilization efficiency. Under partially shading conditions, the P-V curve shows multiple peaks; therefore, the function of the Maximum Power Point Tracking (MPPT) techniques are to track the global power point and avoid operation at the local peaks. One of the most effective methods especially in partial shading conditions is Fuzzy Logic Control (FLC) technique. This paper presents a design of the FLC based MPPT in addition to the scanning system that can differentiate between the global and local MPPs and tracks the global one. The system is formed from a PV array coupled with a DC microgrid through a boost converter. Simulation results are provided using MATLAB/SIMULINK to evaluate the performance of the used MPPT method to track the global power point under various partial shading patterns.
Learning-Based Spam Filters: the Influence of the Temporal Distribution of Training Data

The great number and variety of learning-based spam filters proposed during the last years cause the need in complex and many-sided evaluation of them, taking features of the phenomenon of spam into account. This paper is dedicated to the analysis of the dependence of filter performance on the temporal distribution of training data; the cause of this dependence is the changeability of email. Such analysis provides additional information about the filter quality, and also may be useful for organizing more effective training of the filter. The native Bayes filter is chosen for evaluation in this paper.
MAP Inference via (cid:96) 2 -Sphere Linear Program Reformulation

Maximum a posteriori (MAP) inference is an important task for graphical models. Due to complex dependencies among variables in realistic model, ﬁnding an exact solution for MAP inference is often intractable. Thus, many approximation methods have been developed, among which the linear programming (LP) relaxation based methods show promising performance. However, one major drawback of LP relaxation is that it is possible to give fractional solutions. Instead of presenting a tighter relaxation, in this work we propose a continuous but equivalent reformulation of the original MAP inference problem, called LS-LP. We add the (cid:96) 2 -sphere constraint onto the original LP relaxation, leading to an intersected space with the local marginal polytope that is equivalent to the space of all valid integer label conﬁgura-tions. Thus, LS-LP is equivalent to the original MAP inference problem. We propose a perturbed alternating direction method of multipliers (ADMM) algorithm to optimize the LS-LP problem, by adding a sufﬁciently small perturbation (cid:15) onto the objective function and constraints. We prove that the perturbed ADMM algorithm globally converges to the (cid:15) -Karush–Kuhn–Tucker ( (cid:15) -KKT) point of the LS-LP problem. The convergence rate will also be analyzed. Experiments on several benchmark datasets from Probabilistic In-Baoyuan
Position control of PMSM based on energy-shaping and MTPA principle

The energy-shaping and maximum torque per ampere (MTPA) principle is used to develop the model and position control of permanent magnet synchronous motor (PMSM) in this paper. Firstly, based on the port-controlled Hamiltonian (PCH) systems theory, a PCH position control model of PMSM is established. Secondly, using energy-shaping and MTPA method, the control strategy of PMSM is presented when load torque is known and unknown. The control problem of the PMSM is reduced to the solution of a partial differential equation. The partial differential equation can be transformed into a set of general differential equation by assigning desired interconnection and damping matrix. Finally, the equilibrium stability is also analyzed. The simulation results show that the proposed scheme exhibits good position control and load disturbances attenuation performances.
Digital terrain modelling: A review of hydrological, geomorphological, and biological applications

The topography of a catchment has a major impact on the hydrological, geomorphological. and biological processes active in the landscape. The spatial distribution of topographic attributes can often be used as an indirect measure of the spatial variability of these processes and allows them to be mapped using relatively simple techniques. Many geographic information systems are being developed that store topographic information as the primary data for analysing water resource and biological problems. Furthermore, topography can be used to develop more physically realistic structures for hydrologic and water quality models that directly account for the impact of topography on the hydrology. Digital elevation models are the primary data used in the analysis of catchment topography. We describe elevation data sources, digital elevation model structures, and the analysis of digital elevation data for hydrological, geomorphological, and biological applications. Some hydrologic models that make use of digital representations of topography are also considered.
Real time visualization of large terrain in flight simulation

Three dimensional large terrain is a significant composition of the nature scene in virtual simulation field. This paper focuses on the improvement of algorithms for the implement of view-dependent refinement of large terrain surfaces which are based on the analyses of the relations and bottlenecks between each infrastructure of the whole computer system and related requirements for the real-time flight simulation application. A new implementation of view-dependent refinement of large terrain surfaces is proposed, and an improved view frustum culling algorithm is also presented based on primarily the method of longest edge bisection in a top-down traversal of the mesh hierarchy. The new frame coherence algorithm which improves the display rates is given. Finally, a conclusion is drawn that these improved algorithms really improve the simulation performance.
A Web Environment to Support Teaching Introductory Programming

This study describes a Web environment for supporting the teaching of Introduction to Programming" course, which is taught to around 350 students/semester. The wide variety of student backgrounds and access to resources has rendered this task very challenging. This paper discusses the design, implementation and experiences related to a Web based learning environment. To this end, a web environment which also enables students to write their C programs on a web page is developed, deployed and evaluated.