Full Decoupling Research Articles

P 35 The success of learning from errors – the role of high-gamma EEG and peripheral physiological responses

How humans learn from errors is a matter of great interest in neuroscience, yet many aspects of the underlying brain mechanisms and the role of peripheral physiological processes in error- based learning still remain unclear. Here, we investigated error-related learning in 30 healthy subjects during a classical Eriksen flanker task. Subjects had to use either the left or right hand to respond to the visual stimuli and were instructed to avoid errors in the form of ”slow” trials exceeding a pre-defined time limit. EEG data were acquired with a 128-channel system optimized for detection of high-frequency EEG components. To ensure an optimal signal-to-noise ratio, recordings took place in an electromagnetically shielded cabin and with full optical decoupling of all devices. We acquired peripheral physiological data using a high resolution binocular eye tracker and a two-channel ECG and computed the individual heart rate variability as a parameter previously implicated in learning processes. Consistent with the instruction stressing the importance of speed over accuracy, the number of slow trials decreased during the experiment ( Fig. 1 A). Further, we could show a significant post-error heart-rate deceleration, while pupil size was significantly bigger following error trials compared to correct ones. Both parameters showed an opposite yet similar temporal profile (Fig. 1B). In the EEG data, we found high-gamma band (HGB) spectral power increases in the frequency range up to 120 Hz approx. 100 ms post-error and over the frontal midline region. Across subjects, the amplitude of the individual frontal-midline HGB response was significantly correlated with the individual learning performance, as well as the heart rate variability and error-related pupil size response. Our findings reveal a novel response pattern consisting of central (frontal midline HGB) and peripheral (pupil size, heart-rate variability) components predictive of the individual success in learning from errors and thus open up a new window on the mechanisms contributing to learning via the error-monitoring network.

Assessing resource productivity for industrial parks using adjusted raw material consumption (ARMC)

Conventional resource productivity (RP) evaluation methods for industrial parks (IPs) are usually limited in scope, as they do not differentiate between the different types of resources. The real resource consumption and environmental impact were usually hidden. In response to this limitation, the Adjusted Raw Material Consumption (ARMC) method was introduced. The method took upstream production efficiency and resource grades into consideration. In this way, equivalent primary resource consumption (EPRC) was applied. In this paper, a set of equivalent coefficients estimation methods was established. Tianjin Economic-Technological and Development Area (TEDA) were chosen as a case study to demonstrate the application of ARMC method. By comparison with conventional methods, the ARMC method broadens the scope for calculating resource consumption by including upstream mining and refining of primary resources. It reveals the real resource consumption structure and determines key resource for holistic improvements to RP. Analysis on TEDA shows it has not yet fully achieved full decoupling between resource consumption and economic growth. Several industrial symbiosis activities have already been implemented to reduce aluminum and lead consumptions in TEDA. To more quickly achieve a greater increase in RP, and thus decoupling, efforts to reduce iron and copper consumptions should be made simultaneously. This evaluation is particularly beneficial for IPs, and for the government to promote more targeted measures to improve resource efficiency. This study was first attempt to assess resource consumption structure in IPs using ARMC method. Based on the results, a management procedure for IPs to improve RP value was developed.

The overlapped radial basis function-finite difference (RBF-FD) method: A generalization of RBF-FD

We present a generalization of the RBF-FD method that computes RBF-FD weights in finite-sized neighborhoods around the centers of RBF-FD stencils by introducing an overlap parameter δ∈(0,1] such that δ=1 recovers the standard RBF-FD method and δ=0 results in a full decoupling of stencils. We provide experimental evidence to support this generalization, and develop an automatic stabilization procedure based on local Lebesgue functions for the stable selection of stencil weights over a wide range of δ values. We provide an a priori estimate for the speedup of our method over RBF-FD that serves as a good predictor for the true speedup. We apply our method to parabolic partial differential equations with time-dependent inhomogeneous boundary conditions – Neumann in 2D, and Dirichlet in 3D. Our results show that our method can achieve as high as a 60× speedup in 3D over existing RBF-FD methods in the task of forming differentiation matrices.

Magnetic Resonance Guided Radiation Therapy: Feasibility Study of a Linear Accelerator and Magnetic Resonance-on-Rails System

Comprehensive technical assessment of a MR-guided radiation therapy system, design, and integration of clinical workflows. A therapy vault was designed to house a Linac conventional setup and at the same time to allow a 1.5T MR-on-rails scanner to travel inside the vault at a pre-defined imaging location in the vicinity of the Linac. The Linac is a 6X FF/FFF system with a standard patient treatment table. The MR can travel on ceiling-mounted rails between a dedicated MR simulation suite and the Linac vault, the two rooms being separated by radiation and RF shielding doors. To allow MR imaging in the vault, the Linac and the patient table are stored behind specially designed RF doors. The separation between the Linac and MR was chosen to allow for a full magnetic field decoupling between all sub-components. With the MR at the imaging position the Linac/couch can be operated independently without posing safety risks or sub-optimal performance of the Linac/couch or MR scanner. The patient is moved between MR diagnostic table and Linac table via a patient transfer system operated as a hovercraft device. The MR/Linac configuration was assessed by considering the following aspects: a) magnetic field decoupling by experimental measurements – i.e. field mapping with Hall probes, magnetic pull forces on the Linac table, radiation beam specifications - output/flatness/symmetry, Linac on-board imaging, MR shimming and overall imaging performance – b) RF noise isolation (survey, MR testing), c) safety systems (interlocking system, redundancy measures), d) RT workflows (patient transfer, MR data flow, MR to kV matching), and QC procedures (MR image quality and B0 mapping, Linac/MR). Numerical simulations based on finite elements methods were also performed to model the entire MR-Linac environment including the Linac table. The MR scanner field was generated using a LP optimization technique and the Linac/table was represented as full-scale CAD geometries. The Linac beam performance and its kV imaging system were found to be unaffected by the MR presence in the treatment vault. The effects were measured and monitored over one year. The MR scanner was tested for optimal performance - the shimming and standard imaging procedures passed the clinical requirements. The numerical simulations and associated measurements for the magnetic field decoupling were in good agreement (forces, field mapping). RT workflows utilizing the kV and MR in-room imaging (independent and combined) are currently under development to facilitate the clinical integration of the system. Targeted applications are MR-based RT (adaptive) planning and guidance, fast imaging for the quantification of organ motion. Integrated quality control procedures were also developed for routine monitoring (MR shimming, image distortions – scanner-related and patient-induced, MR-to-kV matching). All aspects investigated support the feasibility of the MR-guided RT system for clinical deployment.

On the decoupling problem of general quasilinear first order systems in two independent variables

The paper deals with the decoupling problem of general quasilinear first order systems in two independent variables. We consider either the case of homogeneous and autonomous systems or the one of nonhomogeneous and/or nonautonomous systems. Necessary and sufficient conditions for the partial or full decoupling of the systems at hand are provided. The conditions involve the properties of eigenvalues and eigenvectors of the coefficient matrix, and provide the differential constraints whose integration leads to the decoupling transformation. Some applications of physical interest are also given.

Mind wandering minimizes mind numbing: Reducing semantic-satiation effects through absorptive lapses of attention.

Mind wandering is associated with perceptual decoupling: the disengagement of attention from perception. This decoupling is deleterious to performance in many situations; however, we sought to determine whether it might occur in the service of performance in certain circumstances. In two studies, we examined the role of mind wandering in a test of "semantic satiation," a phenomenon in which the repeated presentation of a word reduces semantic priming for a subsequently presented semantic associate. We posited that the attentional and perceptual decoupling associated with mind wandering would reduce the amount of satiation in the semantic representations of repeatedly presented words, thus leading to a reduced semantic-satiation effect. Our results supported this hypothesis: Self-reported mind-wandering episodes (Study 1) and behavioral indices of decoupled attention (Study 2) were both predictive of maintained semantic priming in situations predicted to induce semantic satiation. Additionally, our results suggest that moderate inattention to repetitive stimuli is not sufficient to enable "dishabituation": the refreshment of cognitive performance that results from diverting attention away from the task at hand. Rather, full decoupling is necessary to reap the benefits of mind wandering and to minimize mind numbing.

Ising-nematic order in the bilinear-biquadratic model for the iron pnictides

Motivated by the recent inelastic neutron scattering (INS) measurements in the iron pnictides which show a strong anisotropy of spin excitations even above the magnetic transition temperature ${T}_{N}$, we study the spin dynamics within the frustrated Heisenberg model with biquadratic spin-spin exchange interactions. Using the Dyson-Maleev (DM) representation, which proves appropriate for all temperature regimes, we find that the spin-spin dynamical structure factors are in excellent agreement with experiment, exhibiting breaking of the ${C}_{4}$ symmetry even into the paramagnetic region ${T}_{N}<T<{T}_{\ensuremath{\sigma}}$, which we refer to as the Ising-nematic phase. In addition to the Heisenberg spin interaction, we include the biquadratic coupling $\ensuremath{-}K{({\mathbf{S}}_{i}\ifmmode\cdot\else\textperiodcentered\fi{}{\mathbf{S}}_{j})}^{2}$ and study its effect on the dynamical temperature range ${T}_{\ensuremath{\sigma}}\ensuremath{-}{T}_{N}$ of the Ising-nematic phase. We find that this range reduces dramatically when even small values of the interlayer exchange ${J}_{c}$ and biquadratic coupling $K$ are included. To supplement our analysis, we benchmark the results obtained using full decoupling in the DM method against those from different nonlinear spin-wave theories, including the recently developed generalized spin-wave theory (GSWT), and find good qualitative agreement among the different theoretical approaches as well as experiment for both the spin-wave dispersions and the dynamical structure factors.

Interplay between central ECRH and saturated (m, n) = (1, 1) MHD activity in mitigating tungsten accumulation at ASDEX Upgrade

The interplay between central electron cyclotron resonance heating (ECRH) and saturated (m, n) = (1, 1) magnetohydrodynamic (MHD) instabilities in mitigating central W accumulation at ASDEX Upgrade is analysed. The evolution of the intrinsic tungsten density in a typical ASDEX Upgrade H-mode discharge with central ECRH and saturated (1, 1) modes in-between sawtooth crashes is presented. The W density profile evaluated averaging over mode rotation and assuming axisymmetry are deeply hollow inside the q = 1 surface during mode saturation. In order to provide a mode-resolved picture, a new technique for the determination of 2D mode-resolved intrinsic W density maps in the presence of saturated MHD instabilities is developed. For the first time the full decoupling of the impurity density from electron density and temperature contributions to experimental 2D SXR tomographic reconstructions in the presence of saturated MHD activity can be performed. These mode-resolved 2D W density maps reveal that the impurity hole is located inside the displaced core of the saturated (1, 1) mode, while the W density inside the magnetic island is flat. Modelling the W density using the combined neoclassical and gyrokinetic codes NEO and GKW assuming axisymmetry and including the effects of toroidal rotation reproduces the poloidal asymmetries outside of the q = 1 surface correctly, but predicts centrally peaked W density profiles in the centre. This suggests that the hollowness inside the q = 1 surface is tied to the presence of the saturated (1, 1) mode.

Integration of a model-independent interface for RBE predictions in a treatment planning system for active particle beam scanning

Especially for heavier ions such as carbon ions, treatment planning systems (TPSs) for ion radiotherapy depend on models predicting the relative biological effectiveness (RBE) of the particles involved. Such models are subject to intensive research and the choice of the optimal RBE model is a matter of debate. On the other hand TPSs are often strongly coupled to particular RBE models and transition even to extended models of the same family can be difficult. We present here a model-independent interface which allows the unbiased use of any RBE model capable of providing dose–effect curves (even sampled curves) for a TPS. The full decoupling between the RBE model and TPS is based on the beam-mixing model proposed by Lam which is, in contrast to the often-used Zaider–Rossi model, independent of the explicit form of the underlying dose–effect curves. This approach not only supports the refinement of RBE models without adaptations of the TPS—which we demonstrate by means of the local effect model (LEM)—but also allows the comparison of very different model approaches on a common basis. We exemplify this by a comparison between the LEM and a model from the literature for proton RBE prediction.

An evolutionary path for the evolved packet system

New architectural requirements appear with the evolution of mobile networks, such as the provisioning of multihoming or offloading. In general, this requires the design of ad hoc schemes on top of the EPS, which may be seen as an indicator of the need for a back-to-basics architectural analysis. This article analyzes the basic architectural principles of the EPS, and compares them with those of SDN and LISP. We then describe an evolutionary path for the EPS, by showing how, with slight modifications inspired by SDN and LISP, future mobile carrier networks could natively fulfill some of their flexibility and scalability requirements. The key design principles for that are: a generalized use of traffic flow templates (i.e., 5-tuple flows) for more flexible IP flow handling; a full decoupling of control and user plane for flexibility; and an on-demand (or pull-based) state setting at network nodes for scalability. Some examples are given to illustrate the thesis of this article.

Resistant to Change? The European Commission and Expert Group Reform

This article examines how the European Commission has responded to external criticism and demands for the democratisation and reform of the way it uses expert groups in EU policy making. The article analyses the nature and character of the Commission’s dialogue with its critics and the degree and extent to which it was prepared to adapt its existing internal processes and procedures to the reform agenda. Recent theories inform us that organisations respond in different ways to external criticism and demands for reform, including full adaptation, evasion, institutional decoupling and reinterpretation. The main findings suggest that the Commission was not completely resistant to changing its approach to the use of expertise. The Commission reinterpreted its critics’ demands by introducing reforms that defused this external pressure, while protecting the effectiveness of its existing internal ideology and processes. These findings serve to enhance the Commission’s image as an increasingly normalised bureaucracy and reinforce the importance of knowledge and expertise as a key source of Commission legitimacy.

Payment decoupling and intra-European calf trade

The 2003 CAP reform introduced decoupled income transfers as a prominent policy instrument. However, member states were given discretion over the degree and timing of the reform implementation. As a result, different implementation schemes coexist, keeping certain parts of the income support coupled. This coexistence leads to distortions of production incentives, factor misallocations and artificial trade flows. Here, we examine these effects in the beef sector where full decoupling was not obligatory. We derive a sector-specific trade model to examine the effects of different implementation schemes on intra-European calf trade. Empirical results confirm that trade flow distortions occurred.

Stable FLRW solutions in generalized massive gravity

We present exact Friedmann Lemaítre Robertson Walkers (FLRW) solutions in generalized massive gravity where the mass parameters are naturally promoted to Lorentz-invariant functions of the Stückelberg fields. This new dependence relaxes the constraint that would otherwise prevent massive gravity from possessing exact FLRW solutions. It does so without the need to introduce additional degrees of freedom. We find self-accelerating cosmological solutions and show that, with a mild restriction on the region of phase space, these cosmological solutions exhibit full stability, i.e. absence of ghosts and gradient instabilities for all the tensor, vector and scalar modes, for all cosmic time. We perform the full decoupling limit analysis, including vector degrees of freedom, which can be used to confirm the existence of an active Vainshtein mechanism about these solutions.

Critical examination of isolation system design paradigms for a coupled powertrain and frame: Partial torque roll axis decoupling methods given practical constraints

The torque roll axis motion decoupling concept is analytically and computationally studied in a realistic coupled powertrain and frame system using discrete, proportionally damped linear models. Recently, Hu and Singh (2012 [1]) (Journal of Sound and Vibration 331 (2012) 1498–1518) proposed new paradigms to fully decouple such a system. However, critical examination shows that the derivation does not always lead to a physically realizable system, as each powertrain mount is not referenced to a single location. This deficiency is overcome by deriving mount compatibility conditions to ensure realistic mount positions which are incorporated into proposed decoupling conditions. It is mathematically shown that full decoupling is not possible for a practical system, and therefore partial decoupling paradigms are pursued. Powertrain mount design using only the decoupled powertrain achieves better decoupling than minimizing conditions for the coupled system using a total least squares method. Further decoupling is obtained through frame isolation design using a decoupled frame model such that the torque roll mode is dominant over the frequency range considered. Other methods for limiting frame coupling are also briefly discussed.

On-Chip Nanoscale Capacitor Decoupling Architectures for Hardware Security

This paper presents new power analysis attack (PAA) countermeasures for nanoscale cryptographic devices. Specifically, three circuit level architectures called partial decoupling architecture, full decoupling architecture, and randomized switch box architecture are developed and analyzed. The architectures' primary feature is the use of on-chip nMOS gate capacitors as intermediate power storage elements to decouple the power supply from internal low-power modules processing sensitive data. The proposed countermeasures are algorithm independent and allow different tradeoffs between security protection and the incurred overheads. Test benches of the proposed architectures were simulated in 65-nm TSMC CMOS technology. A correlation PAA was performed for each test bench targeting a custom implementation of the advanced encryption standard subbytes operation. All architectures were found to resist the correlation PAA at the power supply, with the more complex architectures also offering protection against invasive attacks. The success value indicator was used to analyze the effectiveness of the countermeasures. It was found that all architectures provided a negative value at the power supply, showing protection against PAAs. We demonstrate that the use of nMOS gate capacitors can help to increase security and present a feasibility analysis focused on the needed decoupling capacitances.

Dielectric and electrical conduction behavior of carbon paste electrochemical electrodes, with decoupling of carbon, electrolyte and interface contributions

The electrical conduction and dielectric (capacitive) properties of electrolyte-filled carbon paste electrochemical electrodes are reported, with the carbon, electrolyte (15% H2SO4), carbon–electrolyte interface and carbon–contact(metal) interface contributions fully decoupled for the first time. Without full decoupling and with the carbon contributions neglected, the carbon–electrolyte specific interfacial capacitance would be much over-estimated and the carbon–electrolyte interfacial resistivity would be much under-estimated. The carbons and electrolyte are comparable in both dielectric constant and resistivity. The specific contact capacitance is increased and the contact resistivity is decreased by adding the electrolyte to a carbon. The electrolyte is more effective than water in enhancing carbon–liquid and paste–contact interfaces. Conductivity is attractive for batteries and supercapacitors; strong dielectric properties are attractive for supercapacitors but not batteries. Exfoliated graphite provides handleability and excellent volumetric and interfacial conductivities. It gives low carbon dielectric constant, but contributes to the interfacial capacitances. Activated graphite nanoplatelet (GNP) gives high carbon and paste dielectric constants and high specific contact capacitance. Activated carbon gives poor volumetric and interfacial conductivities. Exfoliated graphite is even better than carbon black for batteries; GNP is even better than activated carbon for supercapacitors; an exfoliated-graphite/GNP mixture is suitable for both; natural graphite is not competitive for either.

Homonuclear BIRD-decoupled spectra for measuring one-bond couplings with highest resolution: CLIP/CLAP-RESET and constant-time-CLIP/CLAP-RESET

Heteronuclear one-bond couplings are of interest for various aspects of structural analysis of small organic molecules, including for example the distinction of axial and equatorial protons or the use of RDCs as angular constraints. Such couplings are most easily measured from pure doublets in HSQC-type spectra. Recently, the fully decoupled RESET HSQC experiment was reported and several other so-called pure-shift methods followed that allow for the removal of splittings due to homonuclear scalar interactions in one and two-dimensional NMR. In this work we present broadband homonuclear decoupled CLIP/CLAP-RESET experiments based on an isotope-selective BIRD filter element using a recently reported improved version of Zangger–Sterk data chunking. The concatenated FIDs result in multiplets in which most homonuclear splittings are removed while the heteronuclear one-bond couplings are retained. Couplings can be extracted in an IPAP fashion without scaling of subspectra by the use of optimized coherence transfer elements like the COB-INEPT. The method leads to complete homonuclear decoupling for CH groups and CH3 groups in isotropic samples, but leaves residual splittings with antiphase contributions for e.g. CH2 groups due to 2JHH coupling evolution that is not affected by the BIRD element. For this case we present a constant-time version of the proposed BIRD decoupling scheme with full homonuclear decoupling. In addition, the effects of strong coupling are discussed. Strong coupling artifacts cannot be circumvented, but the proposed experiments allow their distinct recognition.

Electronic structure of Ge1 − x − y Si x Sn y ternary alloys for multijunction solar cells

Ternary group-IV alloys have a wide potential for applications in infrared devices and optoelectronics. In connection with photovoltaic applications, they are among the most promising materials for inclusion in the next generation of high-efficiency multijunction solar cells, because they can be lattice matched to substrates as GaAs and Ge, offering the possibility of a range of band gaps complementary to III–V semiconductors. Apart from the full decoupling of lattice and band structures in Ge1 − x − ySixSny alloys, experimentally confirmed, they allow preparation in a controllable and large range of compositions, thus enabling to tune their band gap. Recently, optical experiments on ternary alloy-based films, photodetectors measured the direct absorption edges and probed the compositional dependence of the direct gap. The nature of the fundamental gap of Ge1 − x − ySixSny alloys is still unknown, as neither experimental data on the indirect edges nor electronic structure calculations are available, as yet. Here, we report a first calculation of the electronic structure of Ge1 − x − ySixSny ternary alloys, employing a combined tight-binding and virtual crystal approximation method, which proved to be useful to describe group-IV semiconductor binary alloys. Our results confirm predictions and experimental indications that a 1eV band gap is indeed attainable with these ternary alloys, as required for the fourth layer plan to be added to present-day record-efficiency triple-junction solar cells, to further increase their efficiency, for example, for satellite applications. When lattice matched to Ge, we find that Ge1 − x − ySixSny ternary alloys have an indirect gap with a compositional dependence reflecting the presence of two competing minima in the conduction band. Copyright © 2013 John Wiley & Sons, Ltd.

Coupling in amplitude variation with offset and the Wiggins approximation

Linear amplitude-variation-with-offset (AVO) approximations, which experience a reduction in accuracy as elastic parameter contrasts become large, may be adjusted with second- and higher-order corrections. Corrective terms can be expressed in many ways, but they only serve a meaningful purpose if they provide the same qualitative interpretability as did the linearization. Some aspects of nonlinear AVO can be understood, quantitatively and qualitatively, in terms of coupling — the interdependence of elastic parameter contrasts amongst themselves in their determination of reflection strengths. Coupling, for instance, explains the weak but nonnegligible dependence of the converted wave reflection coefficient on the lower half-space P-wave velocity. This fact can be exposed by expanding the solutions of the Zoeppritz equations in a particular hierarchy of series. Also explainable through this approach is the mathematical importance of what is sometimes referred to as the “Wiggins approximation,” under which [Formula: see text]. This special number is seen to coincide with a full decoupling of density contrasts from [Formula: see text] and [Formula: see text] contrasts at the second order. The decoupling persists across several variations of the nonlinear AVO approximations, including both expressions in terms of the relative changes [Formula: see text], [Formula: see text], and [Formula: see text], and expressions in terms of single-parameter reflectivities.

A Discrete State-Space Control Scheme for Dynamic Voltage Restorers

This paper presents a discrete state-space controller using state feedback control and feed-forward decoupling to provide a desirable control bandwidth and control stability for dynamic voltage restorers (DVR). The paper initially discusses three typical applications of a DVR. The load-side capacitor DVR topology is preferred because of its better filtering capability. The proposed DVR controller offers almost full controllability because of the multi-feedback of state variables, including one-beat delay feedback. Feed-forward decoupling is usually employed to prevent disturbances of the load current and source voltage. Directly obtaining the feed-forward paths of the load current and source voltage in the discrete domain is a complicated process. Fortunately, the full feed-forward decoupling strategy can be easily applied to the discrete state-space controller by means of continuous transformation. Simulation and experimental results from a digital signal processor-based system are included to support theoretical analysis.