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Percutaneous closure of patent ductus arteriosus using a duct occluder has become standard of care in its management especially in children more than 6 months of age, weighing more than 6kg but device embolisation is a potential life-threatening complication and may require immediate open-heart surgery. We describe a case of successful surgical management of a patient in early childhood, in which device has embolised deep into the right pulmonary artery. [ABSTRACT FROM AUTHOR]

Automatic Number Plate Recognition (ANPR) uses number plates to identify vehicles. The goal of an automated vehicle identification system is to identify the vehicle based on the number plate. The system enforces the regulations, parking, etc. It can also be used at the entrance to protect a large area, such as a military zone or the region around important government buildings like the military base, Parliament, Supreme Court, etc. The smart technology recognizes and captures the image of the vehicle. The number plate area of the vehicle is extracted using image segmentation on the image. Optical character recognition is used for character recognition. The performance data may also be compared to database records to determine the car owner, enrollment location, residence, etc. The testing showed that the improved algorithm easily recognized the number plate of a vehicle on genuine photographs. [ABSTRACT FROM AUTHOR]

In this paper, a feasibility study of a randomized space vector switching scheme for three-level inverters is reported. Based on the traditional space vector concept for pulse width modulation (PWM) inverter, the sequence of the space vector is randomized in this scheme. The overall vector, resulting from the randomization, is mathematically identical to that of the traditional space vector. It has been found that the randomized scheme can effectively spread the switching noise over a wide frequency range and at the same time keep the steady-state link capacitor voltage balanced. The proposed scheme has been implemented in real time in a digital controller and its features have been experimentally confirmed. Index Terms--Random PWM methods, space vector control, three-level inverters.

Random pulsewidth modulation (RPWM) techniques for dc-ac power converters usually work well with high-sampling frequency. When RPWM schemes are implemented in digital signal processors (DSP's), the sampling frequency is limited by the speed of the processors. This paper analyzes the noise spectrum of various DSP-implemented RPWM techniques using a statistical approach. The relationship of the noise components and the sampling frequency for both the standard RPWM and the weighted RPWM methods is generalized. The dependency of the noise characteristics on various factors is calculated theoretically and verified experimentally. The generalized noise theory for randomized PWM switching provides useful practical guidelines to the choice of sampling frequency. Index Terms: Harmonics, power inverters, random PWM methods

The authors present a statistical approach to the analysis of random pulsewidth modulation (RPWM) methods which generate PWM signals by comparing a reference modulating function with random numbers or signals. Such an approach is used to analyze and optimize a new weighted RPWM (WRPWM) method and also a standard trapezoidal RPWM method. The WRPWM scheme combines the advantages of the nondeterministic and deterministic PWM methods by adding some deterministic nature into the nondeterministic RPWM method. Both theoretical and experimental results confirm that the optimized WRPWM method has better spectral performance over the standard RPWM schemes and has attractive features such as the potential of third-harmonic boosting, reduced acoustic noise, and minimal low-order harmonics under an overmodulation condition for electronic drive applications.

A convex upper bound of the mixed structured singular value [Mu] is analyzed. The upper bound is based on a multiplier method. It is simple, it can exploit low-rank properties, and it is shown to be less conservative than the well-known (D, G)-scaling. A direct relationship with (D, G)-scaling is given. The upper bound can be modified to one that is continuous with an explicit Lipschitz constant.

We consider a class of symmetric Hopfield networks, with nonpositive synapses and zero thresholds. We call such networks Nonpositive Hopfield networks and address a variety of design and analysis issues connected with their application to a specific form of Error Correcting Coding. In particular we show that this class is naturally suited to work in a unidirectional error environment and hence can find application in unidirectional error correcting coding. We give a necessary and sufficient condition for a set of codewords to be storable in a Nonpositive network. We propose a simple word storage algorithm, which is amenable to on line implementation, and guarantees storage of all storage compatible words. We show that the storage algorithm creates a network that is fundamentally maximally tolerant to physical faults and is free from spurious stationary points, whenever that freedom is available. We also give a word forgetting algorithm; a tight, deterministic bound on the storage capacity, and conditions under which the network created by our storage scheme tolerates a given number of arbitrary physical faults.

Background: Pulmonary embolism (PE) is a life-threatening event with a mortality of -10%. It is relatively uncommon in children and literature regarding the condition is sparse. In adults, the classical clinical presentation is with pleuritic chest pain, hemoptysis, and dyspnea, whereas in children, the presentation is often nonspecific. Materials and methods: Clinical features, risk factors, and outcome of children with PE presenting to our unit between December, 19 and March, 2020 were recorded. Results: Four children [mean age: 10 (6-16) years, 3 females], all presenting with tachycardia and dyspnea were diagnosed with PE. Different risk factors such as deep vein thrombosis, nephrotic syndrome, softtissue infection, and infective endocarditis (IE) were identified in all patients. One child died while others responded to anticoagulation. Conclusion: We aim to highlight the importance of timely recognition of PE in children with known risk factors for the same. Early recognition and timely treatment of PE are critical to save lives. [ABSTRACT FROM AUTHOR]

Security is a critical aspect in many of the latest embedded and IoT systems. Malware is one of the severe threats of security for such devices. There have been enormous efforts in malware detection and analysis; however, occurrences of newer varieties of malicious codes prove that it is an extremely difficult problem given the nature of these surreptitious codes. In this article, instead of addressing a general solution, we aim at malware detection for platforms that have more than one core for performance enhancement. We investigate the utility of multiple cores from the point of view of security, where one of the cores operate as a watchdog. We define a notion of a new metric called LAMBDA (Lightweight Assessment of Malware for emBeddeD Architectures), denoted by, indicating a conceptual boundary between the programs which are allowed to run on a given platform, with the codes that are suspected as malwares. The metric is computed using carefully chosen monitors or features, which are tuples of high-level programs representing OS resources, along with low-level hardware performance counters. In comparison to heavy-weight machine learning techniques, we use an online hypothesis testing, in the form of t -test, to classify a given programunder- test. For applications where security is of prime concern, we propose an additional step based on multivariate analysis to classify the unknown programs that are closer to the threshold with a high degree of confidence. We present experimental results focusing on an ARM-based platform which validate that the proposed approach provides a lightweight, accurate assessment of malware codes for embedded platforms. In addition to it, we also present a security analysis to show the difficulty of a mimicry attack attempting to bypass LAMBDA. [ABSTRACT FROM AUTHOR]

The authors present a rigorous theoretical harmonic analysis of random pulse width modulation (RPWM) method and random pulse position modulation (RPPM) method for dc-dc converters. The theoretical relationships of discrete harmonics, continuous noise and output voltage ripple of the RPWM and RPPM schemes are established and compared with those of a standard deterministic PWM scheme in a buck converter. Limitations in the randomly switched dc-dc converters are highlighted. The theoretical predictions indicate that the randomized schemes generally have an inherent problem in achieving low output voltage ripple due to the low-frequency continuous noise within the pass-band of the converter filter. For dc-dc power conversion, the RPPM method offers much better output voltage performance than the RPWM method. Index Terms--Power converters, power electronics, random pulse-width modulation.

This paper presents a generalized theory which covers both two-level and three-level random pulsewidth modulation (RPWM) schemes. Various three-level RPWM schemes with low switching frequency are presented and compared with two-level schemes. Three-level RPWM schemes have less discrete harmonics and continuous noise than two-level RPWM schemes. They have desirable spectral characteristics and can be employed in high-voltage inverter-fed motor drives. Measurements have confirmed the theory and the attractive features of three-level RPWM schemes.

An analysis and experimental results of the random pulsewidth modulation (RPWM) and random pulse-position modulation (RPPM) methods for dc-dc converters are presented. The characteristics and performance of power converters under two randomized modulations are evaluated. The theoretical relationships of discrete harmonics, continuous noise, and output-voltage ripple of the RPWM and RPPM schemes are established and compared with those of a standard deterministic pulsewidth modulation (PWM) scheme in a buck converter. Limitations in the randomly switched dc-dc converters, which have not been addressed before, are highlighted. Randomized schemes generally have inherent problems in achieving low-output-voltage ripple due to the low-frequency continuous noise within the passband of the converter filter. The inherent low-frequency noise-induced voltage ripple problems of nondeterministic switching methods for dc converters are confirmed experimentally. The performance of the RPPM method is found to be closer to the standard PWM method than that of the RPWM method. For dc-dc power conversion, the RPPM method offers much better output-voltage performance than the RPWM method.