Miracle-dz/UniFAR-FTUs huggingface dataset:
Complete electrode model in EEG: relationship and differences to the point electrode model

In electroencephalography (EEG) source analysis, a primary current density generated by the neural activity of the brain is reconstructed from external electrode voltage measurements. This paper focuses on accurate and effective simulations of EEG through the complete electrode model (CEM). The CEM allows for the incorporation of the electrode size, shape and effective contact impedance into the forward simulation. Both neural currents in the brain and shunting currents between the electrodes and the skin can affect the measured voltages in the CEM. The goal of this study was to investigate the CEM by comparing it with the point electrode model (PEM), which is the current standard electrode model for EEG. We used a three-dimensional, realistic and high-resolution finite element head model as the reference computational domain in the comparison. The PEM could be formulated as a limit of the CEM, in which the effective impedance of each electrode goes to infinity and the size tends to zero. Numerical results concerning the forward and inverse errors and electrode voltage strengths with different impedances and electrode sizes are presented. Based on the results obtained, limits for extremely high and low impedance values of the shunting currents are suggested.
Policy implications for the performance gap of low-carbon building technologies

ABSTRACT It is widely recognized that the actual impact of low-carbon technologies is often lower than predicted by models alone, a phenomenon which has been coined the ‘performance gap’. Despite this awareness, in many instances estimates of both energy savings and renewable energy generation in domestic buildings continue to rely on engineering models and building energy simulations rather than approaches that are based on measured parameters. Much of the existing literature on the performance gap focuses on energy efficiency and is concerned with the quantification of the scale of the performance gap. This paper adds to this body of evidence by drawing retrospectively on a range of grey literature evaluations of low-carbon technologies (including energy-efficiency measures, renewable heat and renewable electricity) in the UK household sector. The focus is on not only the quantification of the performance gap but also the qualitative factors often overlooked, such as installation issues or installer/user behaviour. Recommended policy changes include the development of evaluation standards, the experimentation with pay-for-performance programmes, ensuring that installation standards for low-carbon technologies are being enforced, and taking reasonable steps to ensuring that end users can use any new technology effectively.
Adjustable Inertial Response From the Converter With Adaptive Droop Control in DC Grids

In a dc grid, the inherent inertial support from the dc capacitors is too small to resist step changes or random fluctuations from the intermittent power resources, which results in lower dc voltage quality. In this paper, an adaptive droop control (ADC) strategy is proposed to achieve an increased inertia from the droop controlled converter. The adaptable droop coefficient according to the dc voltage variation enables fast swing of the droop curve, so that the converter can provide inertial power for the dc grid like synchronous generators in ac grids. The design of the ADC including the calculation and limitation of the adaptable droop coefficient is analyzed in detail. The small-signal analysis of the dc grid with ADC is provided to identify its stability issue. Experimental tests on a controller hardware-in-the-loop platform of a low-voltage (LV) dc grid are carried out to validate the proposed method. In this LV dc grid, the proposed ADC is implemented on the energy storage system which provides inertial support to improve the dc voltage quality under different power fluctuations, and smooths the power transmitted to ac grid.
Dual-Mode BPF with Four Transmission Zeros Using S-L Coupling Structure with Quadratic Function Coupling Coefficient

In this letter, a compact microstrip bandpass filter (BPF) with four transmission zeros (TZs) is designed by using a short-stub centered loaded folded dual-mode resonator and an I/O mutual coupled open-stub loaded feedline structure. The coupling structure can realize source-load (S-L) coupling with quadratic function coupling coefficient, which can generate three TZs in the upper-stopband to improve the selectivity. Owing to the intrinsic characteristics of the dual-mode resonator, one extra TZ can be created near the lower passband edge. Finally, a compact BPF with fractional bandwidth (FBW) of 3.5% located at 2.4GHz for WLAN application has been designed and fabricated. Good agreement between simulation and measurement verifies the validity of the design.
Selenium in Brazil-Nut “Milk”: Is It Safe?

Studies on Brazil nut (Bertholletia excelsa H.B.K.) and their products revealed its antioxidant benefits, especially due to the Selenium (Se) level, naturally present in Brazil nuts. In order to study toxicological risks to consumers, the aim of this work was to evaluate the Brazil nut powdered “milk” (by atomization). The powdered “milk” showed Se content of 1.200 μg/100 g after atomization. Thus, when one considers the consumption of a tablespoon (10 g) of the powdered product diluted in a 200 ml glass, 60 μg/Se is proportionally obtained and this value is under the Se Recommended Daily Intake (RDI) for humans. In conclusion, the Se levels found in Brazil nuts “milk” were safe to consumers and higher than soybean milk, vegetable “milk”.
A study of the effect of transient stresses on the fatigue life of RF MEMS switches

Fatigue affects the durability of radio frequency microelectromechanical systems (RF MEMS) devices. It is common to rely on actuation voltage cycles or resonant frequencies shift to estimate the fatigue life of MEMS devices. Actuation of moving mechanical parts within the device causes transient stresses because of transient vibration. Such stresses and stress cycles are difficult to account for when fatigue life is estimated by observing actuation voltage or resonant frequencies shift only. This work investigates the effect of transient stresses on the durability of RF MEMS switch, using a benchmarked finite element‐based structural dynamics model of the switch to generate the stress‐time history of the device. Principal normal stresses are calculated from raw stress data and ordered such that (σ1 ≥ σ2 ≥ σ3). Maximum principal stress amplitudes at pull‐in and pull‐out are calculated, and their corresponding number of cycles are determined by rainflow counting method. A Cumulative damage index (Dc) is determined using Miner's rule. This study revealed that, when transient stresses are taken into consideration, the cumulative damage caused by a single on‐off cycle, of the switch studied, is 1.031 × 10−6, and its life‐to‐failure is 9.7 × 105 on‐off cycles. Whereas the life‐to‐failure of the switch, without considering transient stresses, is approximately 10.3 × 108 cycles. Results are compared with published data for similar switches, and they are in good agreement.
Automatic calculation of three-dimensional margins around treatment volumes in radiotherapy planning

Following the publication of ICRU Report 50, the concepts of GTV (gross tumour volume), CTV (clinical target volume) and PTV (planning target volume) are being used in radiotherapy planning with increasing frequency. In 3D planning, the GTV (or CTV) is normally outlined by the clinician in CT or MRI slices. The PTV is determined by adding margins to these volumes. Since manual drawing of an accurate 3D margin in a set of 2D slices is extremely time consuming, software has been developed to automate this step in the planning. The target volume is represented in a 3D matrix grid with voxel values one inside and zero outside the target volume. It is expanded by centring an ellipsoid at every matrix element within the volume. The shape of the ellipsoid reflects the size of the margins in the three main orthogonal directions. Finally, the PTV contours are determined from the 50% iso-value lines of the expanded volume. The software tool has been in clinical use since the end of 1994 and has mostly been applied to the planning of prostate irradiations. The accuracy is better than can be achieved manually and the workload has been reduced considerably (from 4 h manually to automatically).
Multiple Descriptors for Visual Odometry Trajectory Estimation

Visual Simultaneous Localization and Mapping (VSLAM) systems are widely used in mobile robots for autonomous navigation. One important part in VSLAM is trajectory estimation. Trajectory estimation is a part of the localisation task in VSLAM where a robot needs to estimate the camera pose in order to precisely align the real visited image locations. The poses are estimated using Visual Odometry Trajectory Estimation (VOTE) by extracting distinctive and trackable keypoints from sequence image locations having been visited by a robot. In the visual trajectory estimation, one of the most popular solutions is arguably PnP-RANSCA function. PnP-RANSAC is a common approach used for estimating the VOTE which uses a feature descriptor such as SURF to extract key-points and match them in pairs based on their descriptors. However, due to the sensor noise and the high fluctuating scenes constitute an inevitable shortcoming that reduces the single visual descriptor performance in extracting the distinctive and trackable keypoints. Thus, this paper proposes a method that uses a random sampling scheme to combine the result of multiple key-points descriptors. The scheme extracts the best keypoints from SIFT, SURF and ORB key-point detectors based on their key-point response value. These keypoints are combined and refined based on Euclidean distances. This combination of keypoints with their corresponding visual descriptors are used in VOTE which reduces the trajectory estimation errors. The proposed algorithm is evaluated on the widely used benchmark dataset KITTI where the three longest sequences are selected, 00 with 4541 images, 02 with 2761 images and 05 with 1101 images. In trajectory estimation experiment, the proposed algorithm can reduce the trajectory error of 44%, 8% and 13% on KITTI dataset for the sequence 00, 02 and 05 respectively based on translational and rotational errors. Also, the proposed algorithm succeeded in reducing the number of keypoints used in VOTE as combined with the state-of-the-art RTAB-Map.
Your Wish, My Command – Speeding up Projects in the Transportation Industry Using Ontologies

This paper presents the results of an exploratory study conducted at ALSTOM on the application of knowledge‐centric approaches to the requirements definition process. The original scope of the study concerned the application of ontologies to analyze and improve the quality of specification documents in an industrial context. An additional idea quickly emerged as a collateral benefit of the study to extend the usage of the gathered knowledge base in order to perform computer‐assisted identification of requirements from structured and unstructured documents. The purpose of this new approach is to improve the execution of projects in railway transportation by accelerating the requirements management and development processes and, in particular, the stakeholder requirements capture and elicitation activities.
Discussion of information technology based english teaching system for biological chemistry

At present, biological chemistry engineering science and technology is applied in many areas in China. English is a useful tool for engineers to have international exchange. And biological chemistry engineering science and technology English teaching system based on information technology is becoming very popular method for engineering science and engineers. But the research on IT based English teaching system is ignored by education and industry. Firstly, the research status and development tendency of information technology based English teaching system is discussed; secondly, the main methods of information technology based English teaching system is analyzed; thirdly, we described a new English Teaching System based on information technology model for biological chemistry engineering science and technology; finally, the conclusions of information technology based English teaching system are put forward.
Next-to-leading resummation of cosmological perturbations via the Lagrangian picture: 2-loop correction in real and redshift spaces

We present an improved prediction of Lagrangian resummation theory (LRT), the nonlinear perturbation theory (PT) via the Lagrangian picture originally proposed by Matsubara (2008). Based on the relations between the power spectrum in standard PT and that in LRT, we derive analytic expressions for the power spectrum in LRT up to 2-loop order in both real and redshift spaces. Comparing the improved prediction of LRT with N-body simulations in real space, we find that the 2-loop corrections can extend the valid range of wave numbers where we can predict the power spectrum within 1% accuracy by a factor of 1.0 (z = 0.5), 1.3 (1), 1.6 (2) and 1.8 (3) vied with 1-loop LRT results. On the other hand, in all redshift ranges, the higher-order corrections are shown to be less significant on the two-point correlation functions around the baryon acoustic peak, because the 1-loop LRT is already accurate enough to explain the nonlinearity on those scales in N-body simulations.
Control and Optimization of a Compact 6-Degree-of-Freedom Precision Positioner Using Combined Digital Filtering Techniques

Control and Optimization of a Compact 6-Degree-of-Freedom Precision Positioner Using Combined Digital Filtering Techniques. (December 2011) Jose Christian Silva Rivas, B.S., The University of Texas at Austin Chair of Advisory Committee: Dr. Won-jong Kim This thesis presents the multivariable controller design and implementation for a high-precision 6-degree-of-freedom (6-DOF) magnetically levitated (maglev) positioner. The positioner is a triangular single-moving part that carries three 3-phase permanentmagnet linear-levitation-motor armatures. The three planar levitation motors not only generate the vertical force to levitate the triangular platen but control the platen’s position in the horizontal plane. All 6-DOF motions are controlled by magnetic forces only. The positioner moves over a Halbach magnet matrix using three sets of two-axis Hall-effect sensors to measure the planar motion and three Nanogage laser distance sensors for the vertical motion. However, the Hall-effect sensors and the Nanogage laser distance sensors can only provide measurements of the displacement of all 6-axis. Since we do not have full-state feedback, I designed two Linear Quadratic Gaussian (LQG) multivariable controllers using a recursive discrete-time observer. A discrete hybrid H2/H∞ filter is implemented to obtain optimal estimates of position and orientation, as well as additional estimates of velocity and angular velocity for all 6 axes. In addition, an analysis was done on the signals measured by the Hall-effect sensors, and from there several digital filters were tested to optimize the readings of the sensors and obtain the best estimates possible. One of the multivariable controllers was designed to close the control loop for the three-planar-DOF motion, and the other to close the loop for the vertical motion, all at a sampling frequency of 800 Hz. Experimental results show a position resolution of 1.5 μm with position noise of 0.545 μm rms in the x-and ydirections and a resolution of less than 110 nm with position noise of 49.3 nm rms in z.
Practical implementation of universal digital feedback for characterisation of soft magnetic materials under controlled AC waveforms

Practical implementation of digital feedback (DF) for waveshape control is described in the paper. It is shown that if the system has intrinsically sufficient phase margin then operation of DF can be controlled by changing just the DF gain even though the system gain can vary more than 2 orders of magnitude. Practical tips as well as typical difficulties are also discussed. The provided description should be sufficient to implement DF in any programming language and hardware configuration. Streszczenie. Artykuł opisuje praktyczną implementacją cyfrowego sprzężenia zwrotnego (CSZ). Jeśli system wymuszający ma wystarczający zapas fazy to działanie CSZ może być kontrolowane tylko poprzez zmianę wzmocnienia CSZ nawet jeśli wzmocnienie systemu może się zmnieniać o ponad dwa rzędy wielkości. Podany jest opis praktycznych wskazówek oraz typowych trudności. Zaprezentowany opis CSZ w niniejszym artykule powinien być wystarczający do zaimplementowania CSZ w dowolnym języku programowania i konfiguracji sprzętowej. (Praktyczna implementacja uniwersalnego cyfrowego sprzężenia zwrotnego do badania materiałów magnetycznie miękkich kontrolowanymi przebiegami wymuszenia przemiennego).
Role of Feature Position in recognition of Human Vehicle Interaction

This paper proposes an improvement in the Bag of Words (BoW) model by introducing spatial position of features in interaction representation stage for Human Vehicle Interaction Recognition. The spatial positions of features are incorporated along with feature descriptor to obtain the structural information required to correctly classify different kind of human vehicle interaction. BoW lacks structural information as well as the relationship between spatiotemporal features. This renders this BoW approach, in its basic form, ineffective for human vehicle interaction recognition. The proposed approach enhances the BoW representation by emphasizing the role of spatial feature positions for interaction and incorporates the spatial and temporal relationship between the features. This approach has been tested on the state of the art dataset and achieved accuracy of 92.8%. It has been found that our approach out performs the Bag of Words approach and other state of the art work.
Approximate equations of the theory of liquids in the statistical thermodynamics of classical liquid systems

This review presents the fundamentals of the method of integral equations of the theory of liquids. One of the central problems of the theory, the definition of bridge-functionals, is analyzed. Some applications of the method of integral equations to simple liquid systems are discussed, and the problem of description of complex polyatomic classical systems is considered.
MOOCs Readiness among Malaysian Adult Learners

MOOCs Readiness is defined as a minimum requirement of what learners should know and do to maximize the benefits of MOOCs. This study seeks to investigate the readiness level of adult learners studying in Malaysian Higher Education Institutions. An online questionnaire used consisting of 18 demographic variables and 43 items with 6 constructs: technical, communication and social competencies, self-efficacy, self-directedness and MOOCs Readiness. Sample size is 363 respondents. Descriptive statistics depict competency, demographic profile of learners and level of MOOCs Readiness. Statistical analysis such as EFA, T-test, Pearson Correlation and Multiple regressions were used. All six constructs were reliable with Cronbach Alpha (α) above 0.7. Findings indicate Self-efficacy and Self-directedness constructs were significant for MOOCs Readiness. This study underlines the importance of understanding factors that influence MOOCs Readiness and will assist providers in designing effective MOOCs. (Abstract by authors)
Design and testing of three tailless unmanned aerial vehicle configurations built for surveillance in Antarctic environment

The tailless fixed-wing aircraft have a very compact design and therefore are very attractive as portable unmanned aerial vehicle (UAV) platforms. There is a special need for using such platforms in case of operations in such backlands as Antarctica, because very often the equipment necessary for preparing improvised airfields near Antarctic scientific bases and organizing the UAV flights must be hand-carried. The main aim of this paper is to present the design activity and testing of a number of UAV configurations to be used for aerial monitoring in Antarctic areas and collecting data of local ecosystems. Two UAV flying-wing platforms – MONICA-1 and MONICA-2 – were developed, differing largely with respect to wing-loading and weight-to-power ratios. The light-weight Skywalker X-8 built from the kit and used as a baseline configuration was adapted for special photogrammetric missions. It was found that the main advantage of such light UAV consists in a very simple take-off system (i.e. bungee), however due to low wing loading a usage of this UAV is limited to the so-called ‘weather windows’ of relatively low wind, which do not frequently occur in Antarctica. MONICA-1 is much less sensitive to gust but as a heavy platform it is more difficult to handle in harsh Antarctic environment. To be able to operate in much wider range of the wind, vertical gust and heavy turbulence, typical for Antarctic zones, a special UAV platform – called MONICA-2 – was designed and manufactured. MONICA-2 platform of higher wing loading is smaller than the X-8 and at the same time is able to carry the same photogrammetry equipment. The effort of designers focused on achieving low sensitivity to gust and turbulence by increasing the critical angle of attack and natural static and dynamic stability in the whole range of operational speeds. The paper contains the selected design details and some observations from the flight tests.
Dynamics of a strongly nonlocal reaction–diffusion population model

We study the development of travelling waves in a population that competes with itself for resources in a spatially nonlocal manner. We model this situation as an initial value problem for the integro-differential reaction–diffusion equation with g an even function that satisfies g(y) → 0 as y → ± ∞, , α > 0, 0 < β < 1 + α and λ > 0. We concentrate on the limit of highly nonlocal interactions, λ ≪ 1, focusing on the particular case g(y) = ½ e−|y|, which is equivalent to the reaction–diffusion system Using numerical and asymptotic methods, we show that in different, well-defined regions of parameter space, steady travelling waves, unsteady travelling waves and periodic travelling waves develop from localized initial conditions. A key feature of the system for λ ≪ 1 is the local existence of travelling wave solutions that propagate with speed c < 2, and which, although they cannot exist globally, attract the solution of the initial value problem for an asymptotically long time. By using a Cole–Hopf transformation, we derive a first order hyperbolic equation for the gradient of log u ahead of the wavefront, where u is exponentially small. An analysis of this equation in terms of its characteristics, allowing for the formation of shocks where necessary, explains the dynamics of each of the different types of travelling wave. Moreover, we are able to show that the techniques that we develop for this particular case can be used for more general kernels g(y) and that we expect the same range of different types of travelling wave to be solutions of the initial value problem for appropriate parameter values. As another example, we briefly consider the case , for which the system cannot be simplified to a pair of partial differential equations.