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Asymmetric quantum error-correcting codes (AQCs) may offer some advantage over their symmetric counterparts by providing better error-correction for the more frequent error types. The well-known CSS construction of $q$-ary AQCs i...
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Asymmetric quantum error-correcting codes (AQCs) may offer some advantage over their symmetric counterparts by providing better error-correction for the more frequent error types. The well-known CSS construction of $q$-ary AQCs is extended by removing the $ BBF _{q}$-linearity requirement as well as the limitation on the type of inner product used. The proposed constructions are called CSS-like constructions and utilize pairs of nested subfield linear codes under one of the Euclidean, trace Euclidean, Hermitian, and trace Hermitian inner products. After establishing some theoretical foundations, best-performing CSS-like AQCs are constructed. Combining some constructions of nested pairs of classical codes and linear programming, many optimal and good pure $q$-ary CSS-like codes for $q in { 2,3,4,5,7,8,9}$ up to reasonable lengths are found. In many instances, removing the $ BBF _{q}$-linearity and using alternative inner products give us pure AQCs with improved parameters than relying solely on the standard CSS construction.
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Although the North American power grid has been recognized as the most important engineering achievement of the 20th century, the modern power grid faces major challenges [87]. Increasingly complex interconnections even at the con...
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Although the North American power grid has been recognized as the most important engineering achievement of the 20th century, the modern power grid faces major challenges [87]. Increasingly complex interconnections even at the continent size render prevention of the rare yet catastrophic cascade failures a strenuous concern. Environmental incentives require carefully revisiting how electrical power is generated, transmitted, and consumed, with particular emphasis on the integration of renewable energy resources. Pervasive use of digital technology in grid operation demands resiliency against physical and cyberattacks on the power infrastructure. Enhancing grid efficiency without compromising stability and quality in the face of deregulation is imperative. Soliciting consumer participation and exploring new business opportunities facilitated by the intelligent grid infrastructure hold a great economic potential.
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A new cloud dynamics and radiation database (CDRD) precipitation retrieval algorithm for satellite passive microwave (PMW) radiometer measurements has been developed. It represents a modification to and an improvement upon the con...
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A new cloud dynamics and radiation database (CDRD) precipitation retrieval algorithm for satellite passive microwave (PMW) radiometer measurements has been developed. It represents a modification to and an improvement upon the conventional cloud radiation database (CRD) algorithms, which have always been prone to ambiguity. This part 2 paper of a series describes the methodology of the algorithm and the modeling verification analysis involved in creating a synthetic CDRD database for the Europe/Mediterranean basin region. This is followed by a proof-of-concept analysis, which demonstrates that the underlying CDRD theory based on use of meteorological parameters for reducing retrieval ambiguity is valid. This paper uses a regional/mesoscale model, applied in cloud resolving model (CRM) mode, to produce a large set of numerical simulations of precipitating storms and extended precipitating systems. The simulations are used for selection of millions of meteorological/microphysical vertical profiles within which surface rainfall is identified. For each of these profiles, top-of-atmosphere brightness temperature (TB) vectors are calculated (the vector dimension associated with the number of relevant cm–mm wavelengths and polarizations), based on an elaborate radiative-transfer equation (RTE) model system (RMS) coupled to the CRM. This entire body of simulation information is organized into the CDRD database, then used as a priori knowledge to guide a physical Bayesian retrieval algorithm in obtaining rainfall and associated precipitation parameters from the PMW satellite observations. We first prove the physical validity of our CRM-RMS simulations, by showing that the simulated TBs are in close agreement with observations. Agreement is demonstrated using dual-channel-frequency TB manifold sections, which quantify the degree of overlap between the simulated and observed TBs extracted from the full manifolds. Nevertheless, the salient result of this paper is a pro- f that the underlying CDRD theory is valid, found by combining subdivisions of the invoked meteorological parameter ranges of values and showing that such meteorological partitioning associates itself with distinct microphysical profiles. It is then shown that these profiles give rise to similar TB vectors, proving the existence of ambiguity in a CRD-type algorithm. Finally, we show that the CDRD methodology provides significant improvements in reducing retrieval ambiguity and retrieval error, especially for land surface backgrounds where contrasts are typically small between the rainfall TB signatures and surface emission signatures.
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This paper reviews the current state of loudspeaker-based spatial sound reproduction methods from technical perspective as well as perceptual perspective. A nomenclature is developed that allows for a strict separation between the...
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This paper reviews the current state of loudspeaker-based spatial sound reproduction methods from technical perspective as well as perceptual perspective. A nomenclature is developed that allows for a strict separation between these two perspectives. The physical fundamentals, practical realization, and results from perceptual studies are discussed for a number of well-established and emerging reproduction techniques. Further, the paper outlines novel approaches to spatial sound evaluation in terms of perceived quality and provides a comparison of current approaches.
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Minimally invasive and less invasive procedure is becoming more and more common in medical therapy. Image guidance is an indispensable component in minimally invasive procedures by providing critical information about the position...
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Minimally invasive and less invasive procedure is becoming more and more common in medical therapy. Image guidance is an indispensable component in minimally invasive procedures by providing critical information about the position of the target sites and the optimal manipulation of the devices, while the field of view is limited to naked eyes due to the small incision. Registration is one of the enabling technologies for computer-aided image guidance, which brings high-resolution pre-operative data into the operating room to provide more realistic information about the patient's anatomy. In this paper, we survey the recent advances in registration techniques applied to minimally and/or less invasive therapy, including a wide variety of therapies in surgery, endoscopy, interventional cardiology, interventional radiology, and hybrid procedures. The registration approaches are categorized into several groups, including projection-to-volume, slice-to-volume, video-to-volume, and volume-to-volume registration. The focus is on recent advances in registration techniques that are specifically developed for minimally and/or less invasive procedures in the following medical specialties: neuroradiology and neurosurgery, cardiac applications, and thoracic-abdominal interventions.
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This paper studies the effect of stator winding configuration on the performance of five-phase induction machines under healthy as well as faulty conditions. The study compares two connections, namely, star and pentagon connection...
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This paper studies the effect of stator winding configuration on the performance of five-phase induction machines under healthy as well as faulty conditions. The study compares two connections, namely, star and pentagon connections. The comparison is conducted using both simulation and experimental results. The steady-state model based on symmetrical components theory is introduced for both connections with one-line open due to a converter fault, and the corresponding machine characteristic curves are estimated. During faults, two alternatives for machine operation are possible, namely, open-loop control and optimal current control. While the first alternative corresponds to higher torque ripple and unbalanced winding currents, the second option necessitates unbalanced phase voltages and typically an increased dc-link voltage to source the required optimal currents. Consequently, an increase in the employed semiconductor device rating is required, which is a critical design factor particularly in medium-voltage applications. A new V/f control technique is proposed to ensure disturbance-free operation with one-line open for both winding connections. Based on the unbalanced machine model and experimental verification, the derating factors that ensure safe machine operation for both winding connection alternatives are calculated. The comparison between the two connections shows the superiority of the pentagon connection under fault conditions in terms of efficiency, average torque, torque ripples, and derating factor.
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Today's exploding demand for faster, more reliable, and ubiquitous radio systems in communication, instrumentation, radar, and sensors poses unprecedented challenges in microwave and millimeter-wave engineering. Recently, the pred...
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Today's exploding demand for faster, more reliable, and ubiquitous radio systems in communication, instrumentation, radar, and sensors poses unprecedented challenges in microwave and millimeter-wave engineering. Recently, the predominant trend has been to place an increasing emphasis on digital signal processing (DSP). However, while offering device compactness and processing flexibility, DSP suffers fundamental drawbacks, such as high-cost analog-digital conversion, high power consumption, and poor performance at high frequencies.
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Five-phase induction machines are generally modeled using multiple dq planes or using a phase variable model. This paper considers modeling five-phase induction machines using a voltage-behind-reactance (VBR) configuration. This c...
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Five-phase induction machines are generally modeled using multiple dq planes or using a phase variable model. This paper considers modeling five-phase induction machines using a voltage-behind-reactance (VBR) configuration. This configuration lends itself suitable for time-domain circuit-based simulators as the MATLAB/Simulink SimPowerSystems (SPS) toolbox. The stator electrical dynamics are represented in five-phase coordinates, while the rotor electrical circuit is modeled using rotor flux linkage as the state variable and expressed in the dq stator reference frame. The VBR model is equivalent to a conventional dq model; however, it facilitates the connection of an external inductance without affecting numerical accuracy and calculation efficiency. It also facilitates the simulation of different winding connections, series-connected multimotors, and open phase(s) conditions. The model is, first, derived for a magnetically linear system and then it is extended to include the effect of magnetic saturation. The flux correction method is used to represent the effect of magnetic saturation with a simple modification to represent the effect of cross coupling between fundamental and third sequence planes due to saturation effect. The dynamic cross saturation is considered by adding compensating terms that depend on magnetizing inductance variation. The proposed model is experimentally verified using a prototype 1.5-hp five-phase induction machine under different operating conditions.
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We are now developing a prototype of a 3000-m class underwater glider for virtual mooring. The vehicle glides back and forth between the sea surface and the seabed collecting ocean data at a specific point. Hydrodynamic forces act...
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We are now developing a prototype of a 3000-m class underwater glider for virtual mooring. The vehicle glides back and forth between the sea surface and the seabed collecting ocean data at a specific point. Hydrodynamic forces acting on the half-size model were measured to determine the optimal wing shape. Next, to obtain the dynamical–hydrodynamic coefficients, forced oscillation tests were carried out using the optimally shaped model. Finally, the motions of the glider were simulated using the hydrodynamic coefficients obtained from these model experiments. The experimental and calculated results are shown in this paper.
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Practical mobile communication systems suffer from time-variant channel fading and cochannel interference, both of which give rise to challenges concerning strategy design and performance analysis in wireless relay networks. Altho...
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Practical mobile communication systems suffer from time-variant channel fading and cochannel interference, both of which give rise to challenges concerning strategy design and performance analysis in wireless relay networks. Although these two aspects have attracted concerns in recent studies, most researchers still focused on dealing with a single problem and avoided intricate joint considerations. In this paper, we investigate the cooperative strategies for the communications of two cochannel pairs over time-correlated Rayleigh channels, and the system consists of a relay-assisted pair (Pair 1) along with a direct transmission pair (Pair 2). We begin with a theoretical evaluation on a conventional relay selection (RS) algorithm that maximizes outdated signal-to-interference-plus-noise ratio (M-SINR), and then develop a more sophisticated method that involves extra statistical and interference information based on the concept of minimizing outage probability (MOP). Closed-form outage probability expressions are derived for both pairs with each RS algorithm, and the MOP-type selection is confirmed to outperform M-SINR in robustness against channel fluctuation when the network operates on medium-to-high signal-to-noise ratio (SNR). Implementation issues of the RS methods are discussed to clarify their overhead and to support their practicability. Further, an interference control scheme is proposed to guarantee Pair 2 communication quality under either RS algorithm by disqualifying the relays that probably cause severe cochannel interference to Pair 2. The interference control mechanism is carried out via a novel threshold parameter $varepsilon$ that represents the tolerance of outage performance degradation of Pair 2 resulting from interference. The closed-form analysis validates that the given $varepsilon$ is rational for an arbitrar- network scenario, and it can balance the two pairs' outage behavior under a proper configuration. We reveal the influence of factors such as average SNR, transmit rate, and network topology on system performance to make a comprehensive comparison between diverse cooperative strategies.
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